Author Topic: Power supply advice please (I live in the UK)  (Read 5694 times)

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Offline HobGoblynTopic starter

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Power supply advice please (I live in the UK)
« on: December 06, 2018, 10:34:05 pm »
Been watching EEVblog #168 How to set up an Electronics Lab

Been into electronics since a kid (used to build kits from Tandy's in the 1970's), now I want to take up the hobby in a serious way.

Now due to ill health, I've had to retire at 54 (don't want any sympathy), haven't got loads of spare money, but want to set up a reasonable lab, so that I can start learning properly and have most things I could need. 

Not to worried about components, can get them cheap as and when needed (got a load of caps, resistors etc, plus a load of Ardunio bits to be getting on with). But I want to get the big things now, due to finances, I don't want to have to plead with my lovely wife to buy big  (for my finances)  items in months to come, I'd rather get most of it over with now.

I have some things already, have a  Hantek DS05102P Oscilloscope, have a couple of meters.

I've been going through the youtube blog and Dave recommends getting hold of an analogue Oscilloscope. Looking at ebay, they don't seem very cheap, I presume this isn't really needed?

I do need a power supply, Dave suggests getting a kit, but I can't find any on the UK.  When looking at pre-built ones, I do see a lot of similar looking (presumed made by same company and rebadged) power supplies on ebay/amazon. Was thinking about something like this

https://www.amazon.co.uk/dp/B01E7OGHJM/?coliid=II5WG08YUD1N2&colid=L5N3DCOD52K1&psc=0&ref_=lv_ov_lig_dp_it

But reviews on things like power supplies and soldering stations all seem very mixed, or numerous so called different sites all recomending exactly the same top 10 (suspect they are fake review sites).   Thoughts on a power supply for a beginner, is the one I selected suitable?

My soldering iron is okish (Antex Xs25w) but not a soldering station, video says I must have a soldering station. That's a minefield as there's a load of rebadged cheap stuff out there. Any advice on a cheapish good one?

Then he recommends getting a hot air rework station, again loads around, haven't a clue whether they are good or cheap crap.  Any suggestions for a cheapish good one please?

Most other things in the vid I already own. I know it's a bit of a how long is a piece of string question, I don't expect to be working on mains voltage stuff that much, only if repairing something that breaks.

Many thanks

Hob




 

Offline Totalsolutions

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Power supply advice please (I live in the UK)
« Reply #1 on: December 06, 2018, 11:25:24 pm »
Hi Hob
Same here I can fix things as they break. Take a look at “My Mate Vince “ on  YouTube.  I use soldering irons , Weller but 4 or 5 with different bits and wattage, but not a hot air rework station (yet). Good quality basic tools from Wera  or CK or Wiha. Even Stanley and Draper pro. All good brands really. A very good programmable power supply in valuable. Get your Xmas list in.
« Last Edit: December 06, 2018, 11:27:28 pm by Totalsolutions »
Paul
 
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Offline Jwillis

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Re: Power supply advice please (I live in the UK)
« Reply #2 on: December 06, 2018, 11:51:14 pm »
The biggest expense on a linear supply is the transformer so many companies get around that by using a switching supply in place of the bulky expensive transformer.So a cheap power supply will do fine that delivers 2 or 3  amps at 20 to 30 volts is fine.
You don't need a soldering station right off the start .There are adjustable soldering irons that will do fine for the beginner.
They won't have the power as a fancy station but 50 to 60 watts has served people well for years.If you plan on using SMC (Surface  Mount Components) then a a hot air work station is a must . But you could get by with a hand held hot air gun similar to this
It probably won't replace a large chip but smaller components it would probably be alright.
Cheap and good is a hard proposition.
 
 
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Offline Terry01

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Re: Power supply advice please (I live in the UK)
« Reply #3 on: December 07, 2018, 12:06:36 am »
I have the 30v 5A version of that power supply and it's served me well for 18 months-ish. I like it as it has all the safety features on it and is quite accurate and it also hasn't blew up or electrocuted me even though i've made loads of beginner mistakes!  :-+
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Offline tggzzz

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Re: Power supply advice please (I live in the UK)
« Reply #4 on: December 07, 2018, 12:21:23 am »
There's a good argument to be made that if you can't specify what you need and why, then you don't need it.

With skill and imagination, you can get away with remarkable little equipment. For example, I designed and built my first computer (6800+128bytes of RAM, switches and LEDs) with only the front panel switches and LEDs and a multimeter. Learned a heck of a lot :)

Your question about PSUs... The answer very much depends on the required power and voltage. I have a few old Farnell/Coutant PSUs that I ought to flog.

Consider going to nearby hamfests; there is a lot of surplus equipment there, some of which will be good value.

Consider contacting a local Hackspace/Makerspace; they will have equipment and - more importantly - experienced people with ideas.

Look on gumtree, and on fleabay for local items that you could examine before buying them with cash.
There are lies, damned lies, statistics - and ADC/DAC specs.
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Offline boffin

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Re: Power supply advice please (I live in the UK)
« Reply #5 on: December 07, 2018, 12:28:16 am »
Been watching EEVblog #168 How to set up an Electronics Lab
...

  • Your existing scope will be (more than) fine. Understanding how a scope does what it does is where an analogue is better, but yours will be more than fine
  • If you just need low (<12, 1A) power supply, watch Dave's video on the $20 power supply, and have a look at the eevblog thread on here for that subject
  • For a cheap meter it's hard to beat the Aneng AN8008 (or 8002)
  • For an inexpensive soldering iron, try the Yihau 947-II or Quicko T12-947 (I put a video on youtube comparing them)
 
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Offline james_s

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Re: Power supply advice please (I live in the UK)
« Reply #6 on: December 07, 2018, 12:32:50 am »
There are lots of good power supplies out there on the used market. It depends largely on what you plan to do with it, but I generally suggest a linear bench supply with at least two independent outputs of 0-20V or so capable of delivering at least an amp. More current is always nice, a constant-current mode is highly desirable although not absolutely mandatory at least for lower current supplies.

Switching PSUs have their place but I do not recommend them as a basic bench supply. I also do not like PSUs that have digital controls, they look fancy yes, but nothing beats the usability of an old fashioned analog knob. Digital meters can be nice, but again I personally prefer analog.
 
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Offline cdev

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Re: Power supply advice please (I live in the UK)
« Reply #7 on: December 07, 2018, 04:20:43 am »
This is probably the best place in the world to ask and get advice on setting up a beginners lab. Just don't jump on the first thing you buy, Wait until you know you will use something and that its the best bang for your buck and you'll do well. Also wait until you can get a good deal.
"What the large print giveth, the small print taketh away."
 
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Offline spec

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Re: Power supply advice please (I live in the UK)
« Reply #8 on: December 07, 2018, 08:49:39 am »
This is the best values for money lab PSU and the ideal specification for home electronics- I have three of these (they are linear by the way- one reviewer on ebay claims that they are switch mode?)

https://www.ebay.co.uk/p/Adjustable-DC-Power-Supply-30v-10a-Variable-Precision-Digital-Lab-PSU-Clip-Cable/23025566378
« Last Edit: December 07, 2018, 09:03:21 am by spec »
 
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Offline bd139

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Re: Power supply advice please (I live in the UK)
« Reply #9 on: December 07, 2018, 08:53:35 am »
I wouldn’t buy any cheap supplies when you can get a decent TTi one here in the UK for not much more and sometimes less money!

Look out for Thurlby / TTi PL320/330 units on eBay. Occasionally they turn up for £30-40 or at hamfests for £20-40. They were £300-400 a piece new. I paid £40 each for mine from eBay with delivery. They are professional supplies, have service manuals available and are pretty much everything proof and have no fan.

I wouldn’t buy an analogue oscilloscope now. Even the newest ones are prone to packing in. I spent a fair amount of time fixing dead ones and it’s a pain if you are only just starting out.
« Last Edit: December 07, 2018, 08:56:55 am by bd139 »
 
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Offline Terry01

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Re: Power supply advice please (I live in the UK)
« Reply #10 on: December 07, 2018, 09:14:19 am »
I wouldn’t buy any cheap supplies when you can get a decent TTi one here in the UK for not much more and sometimes less money!

Look out for Thurlby / TTi PL320/330 units on eBay. Occasionally they turn up for £30-40 or at hamfests for £20-40. They were £300-400 a piece new. I paid £40 each for mine from eBay with delivery. They are professional supplies, have service manuals available and are pretty much everything proof and have no fan.

I wouldn’t buy an analogue oscilloscope now. Even the newest ones are prone to packing in. I spent a fair amount of time fixing dead ones and it’s a pain if you are only just starting out.

I would agree with that. I am also relatively new to electronics too.
I got an analogue scope first then a digital one a couple months later and my analogue scope is still living under the bed, where I use my digital scope 99.9% of the time.
I would also advise to just get digital. You can get a decent 2nd hand Rigol or whatever quite cheap, even £250 will get you a nice one.
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Offline spec

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Re: Power supply advice please (I live in the UK)
« Reply #11 on: December 07, 2018, 09:25:57 am »
I wouldn’t buy any cheap supplies when you can get a decent TTi one here in the UK for not much more and sometimes less money!
There is innuendo in what you say. If you buy wisely, cheap (value for money) does not mean not decent. It is also important to keep things in perspective. A lab PSU, after all is said and done, needs to provide stable volts and controllable amps. For home work it does not need, profiles, IEEE program interface or to make coffee. In fact, in the interests of simplicity, it is better if it does not.

Look out for Thurlby / TTi PL320/330 units on eBay. Occasionally they turn up for £30-40 or at hamfests for £20-40. They were £300-400 a piece new. I paid £40 each for mine from eBay with delivery. They are professional supplies, have service manuals available and are pretty much everything proof and have no fan.
AFAIK that PSU is 32V at 3A whereas the PSU I recommended is 0V to 30V at 0A to 10A. Also if that Thurlby unit goes wrong, it will be difficult and costly to fix. BTW, I am not a big fan of Thurlby PSUs. We had a load of them at work and they were nothing but trouble.

I know of quite a few people who have needlessly bought fancy equipment which goes wrong and after vain attempts to fix it, the equipment is just left to rot.

The other thing is that, with a couple of mouse clicks, you could have a very serviceable PSU to use within a couple of days, and if you need another, just do the same thing again. And you would have a PSU that would be more than adequate for home electronics work. Not that long ago that ebay lab PSU would have been the most wonderful PSU imaginable, certainly much better than the lab PSUs we had at work. Buying second hand takes time and is a big risk, especially for a newbee, and going to fests also takes time.

I wouldn’t buy an analogue oscilloscope now. Even the newest ones are prone to packing in. I spent a fair amount of time fixing dead ones and it’s a pain if you are only just starting out.
That may be your experience, but it is most probably because you have been buying the wrong scopes. If you get a decent, simple scope, they last for years without any problems. BTW, you can get plenty of problems with digital scopes. :)

On the subject of digital (storage) versus analog (real time) scopes for a beginners, that is a difficult call. Personally, I would advise an analog scope, because you get much closer to seeing what the electrons are actually doing when they are doing it.

There is also a big debate about bandwidth. Some people argue that bandwidth does not matter. I take the opposite view and would say that the minimum bandwidth scope that you should get is 10MHz and ideally 100Mz. With a digital scope and a low bandwidth analogue scope you can loose a lot of the waveform which may be why a particular circuit is not working. A good example is high frequency ringing at a MOSFET gate or ground bounce on a logic signal which may be causing erroneous clocking.

 
« Last Edit: December 07, 2018, 10:09:41 am by spec »
 

Offline Terry01

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Re: Power supply advice please (I live in the UK)
« Reply #12 on: December 07, 2018, 09:43:53 am »
Just read back and see the OP already has a Hantek digital scope. My bad....sorry!

I had a similar Hantek scope before I got my Rigol and to be honest the Hantek never caused me any problems and did everything I needed it to. It was a great very simple wee scope to learn on and if I am honest the extra features on the Rigol I have now are just a luxury, I didn't "need" them it's just nice to have them.

One thing is for sure, you'll get lots of opinions from lots of people with plenty experience and knowledge so you'll have the best chance of getting the best stuff for you.
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Offline jpb

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Re: Power supply advice please (I live in the UK)
« Reply #13 on: December 07, 2018, 10:19:22 am »
I would second the recommendation for TTi supplies (second hand). I have three supplies, and Agilent an Hameg and a TTi (which I bought first) but it is the TTi that I use all the time. I note that some people report trouble with TTi supplies and others that they never go wrong - my experience has been the latter. They have been around a long time and probably the more recent supplies are better than the older ones.

I'd also say to get a linear supply rather than switched mode. For electronics you aren't likely to need a huge amount of current so 3A is fine and similarly you probably won't need to go above 30V (probably most circuits will be under 20V though some things like a 24V supply). Linear are simple and low noise and the low efficiency doesn't matter (in my view) in a bench supply.
 

Offline jc101

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Re: Power supply advice please (I live in the UK)
« Reply #14 on: December 07, 2018, 10:20:47 am »

I do need a power supply, Dave suggests getting a kit, but I can't find any on the UK.  When looking at pre-built ones, I do see a lot of similar looking (presumed made by same company and rebadged) power supplies on ebay/amazon. Was thinking about something like this

https://www.amazon.co.uk/dp/B01E7OGHJM/?coliid=II5WG08YUD1N2&colid=L5N3DCOD52K1&psc=0&ref_=lv_ov_lig_dp_it

But reviews on things like power supplies and soldering stations all seem very mixed, or numerous so called different sites all recomending exactly the same top 10 (suspect they are fake review sites).   Thoughts on a power supply for a beginner, is the one I selected suitable?

Many thanks

Hob

If your near Cambridge I have a spare Maplin N27GG PSU "80W Constant Power Switching Mode Power Supply" (you'd have to google the code for specs etc.).  All complete in it's original box.  I've been meaning to either put it up here or on eBay for ages but not got round to it.  Pretty sure it's been kicking around here for a while and surfaced when hunting through boxes for something else.  Now I keep moving the box around in my never ending game of office space tetris.
 

Offline bd139

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Re: Power supply advice please (I live in the UK)
« Reply #15 on: December 07, 2018, 11:11:56 am »
I wouldn’t buy any cheap supplies when you can get a decent TTi one here in the UK for not much more and sometimes less money!
There is innuendo in what you say. If you buy wisely, cheap (value for money) does not mean not decent. It is also important to keep things in perspective. A lab PSU, after all is said and done, needs to provide stable volts and controllable amps. For home work it does not need, profiles, IEEE program interface or to make coffee. In fact, in the interests of simplicity, it is better if it does not.

Yes indeed. Current limit is killer feature number one.

Look out for Thurlby / TTi PL320/330 units on eBay. Occasionally they turn up for £30-40 or at hamfests for £20-40. They were £300-400 a piece new. I paid £40 each for mine from eBay with delivery. They are professional supplies, have service manuals available and are pretty much everything proof and have no fan.
AFAIK that PSU is 32V at 3A whereas the PSU I recommended is 0V to 30V at 0A to 10A. Also if that Thurlby unit goes wrong, it will be difficult and costly to fix. BTW, I am not a big fan of Thurlby PSUs. We had a load of them at work and they were nothing but trouble.

I know of quite a few people who have needlessly bought fancy equipment which goes wrong and after vain attempts to fix it, the equipment is just left to rot.

The other thing is that, with a couple of mouse clicks, you could have a very serviceable PSU to use within a couple of days, and if you need another, just do the same thing again. And you would have a PSU that would be more than adequate for home electronics work. Not that long ago that ebay lab PSU would have been the most wonderful PSU imaginable, certainly much better than the lab PSUs we had at work. Buying second hand takes time and is a big risk, especially for a newbee, and going to fests also takes time.

On the subject of the Thurlby supplies, they are very easy to fix (I've only had to fix one out of the 10 or so I've owned and that was trashed when I got it) and AIM TTi still stock spares for them so you can actually get the bits. I wouldn't buy their higher end digital units exactly based on your earlier complexity argument. The basic CC/CV PL series are rock solid though. 10A in the hands of a new user is dangerous IMHO. I haven't used more than about 2-3A for years myself.

The problem with the cheaper new supplies is they all universally have critical design flaws. The Tenma units for example tend to just pack in. The IC on them has the markings filed off as well so chuck it in the bin or deal with Farnell/CPC returns if it goes wrong (mightmare). The switching units like the one you suggested tend to just spontaneously explode or the displays give out in no time at all. The cheap Mastech linear ones, the tap switch relay gives out, exceeds the SOA of the pass transistor and then dumps the whole unregulated supply into your project. Phut! Not good experience. I've fixed those...

You're doing yourself an injury right away if you're not using half decent equipment when learning or starting out IMHO. You don't need a brand new Keysight supply, but something that does what it says on the tin you can trust.

I wouldn’t buy an analogue oscilloscope now. Even the newest ones are prone to packing in. I spent a fair amount of time fixing dead ones and it’s a pain if you are only just starting out.
That may be your experience, but it is most probably because you have been buying the wrong scopes. If you get a decent, simple scope, they last for years without any problems. BTW, you can get plenty of problems with digital scopes. :)

I've fixed a lot of good quality analogue scopes - 30+ at this point across Tek, Hameg, Philips, LG, Kenwood, HP. And I worked for a T&M department back in the day. Look though my forum history. There are no decent, simple analogue scopes left now which aren't likely to give up on you.

A broken analogue scope is an intellectual playground and an excellent learning tool but might interrupt your work and critical path. That's up to the buyer.

On the subject of digital (storage) versus analog (real time) scopes for a beginners, that is a difficult call. Personally, I would advise an analog scope, because you get much closer to seeing what the electrons are actually doing when they are doing it.

There is also a big debate about bandwidth. Some people argue that bandwidth does not matter. I take the opposite view and would say that the minimum bandwidth scope that you should get is 10MHz and ideally 100Mz. With a digital scope and a low bandwidth analogue scope you can loose a lot of the waveform which may be why a particular circuit is not working. A good example is high frequency ringing at a MOSFET gate or ground bounce on a logic signal which may be causing erroneous clocking.

Minimum 20MHz ideally 100MHz for me here. I've got a 60MHz digital (old TDS210) and 250MHz (475A) analogue at both extremes. The digital one gets most of the work because to be honest it's more covenient. I had a Rigol DS1054Z but I didn't use it for any of its strengths (mainly memory depth) so it went.

I suggest a digital scope simply because at the two opposite extremes of the timebase, analogue scopes are terribly difficult to use, even the good ones. At low sweep speed there is no persistence and at the high end, even on a properly set up analogue unit, there is very little brightness. Digital scopes don't have that and all of the disadvantages of earlier digital scopes like aliasing are pretty much moot these days. The hantek is probably fine. And there's the inevitable decisive "autoset" feature which is great for new users who don't know how to get the scope into a known state.
« Last Edit: December 07, 2018, 11:15:28 am by bd139 »
 

Offline amlu

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Re: Power supply advice please (I live in the UK)
« Reply #16 on: December 07, 2018, 01:03:30 pm »
power supply - one of those modules, depending on how many Volts/Amps you need.
https://rdtech.aliexpress.com/store/all-wholesale-products/923042.html?spm=2114.12010108.nav-list.1.42b692b7mWKYGc

Power it up with SMPS of your choice, can be old laptop adapter, can be a meanwell brick.
 

Offline CJay

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Re: Power supply advice please (I live in the UK)
« Reply #17 on: December 07, 2018, 02:05:06 pm »
Another vote for the TTi PSUs, the GPIB programmable all singing and dancing ones don't look much fun to repair if faulty but the simple ones are trivial to repair if you manage to kill one or find a faulty one for cheap, they are pretty bombproof unless you do something really silly.

The Farnell L(T)30 variants are also good, simple and pretty solid performers, again easy to repair and have bog standard parts in them. Though they are *old*, they're still very usable.


The DPS Buck, boost modules are pretty good too apparently, haven't tried one myself yet (keep meaning to order one) but they look usable and can be fed from a dirt cheap laptop PSU.

As for 'scopes, there are plenty of cheaper analog scopes out there, late model Hamegs are a fairly safe bet but you've already got a halfway decent digital scope so I'd spend the time learning its limitations first, you'll probably find it's more than adequate for your needs, at least in the short term and possibly far longer.

Don't fall into the trap of thinking you have to have all the test gear because you really don't, there's nothing wrong with having lots of test gear (only my wallet stops me) but it's absolutely not necessary to have a 0.1PPM 27.5 digit meter and a spectrum analyser capable of DC-Light, the majority of projects and repairs only need simple gear and it's really easy to get yourself very confused when you have too much data.
 

Offline bd139

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Re: Power supply advice please (I live in the UK)
« Reply #18 on: December 07, 2018, 02:21:17 pm »
Warning on the Farnell supplies. The E/LT ones are missing a couple of essential diodes, one across the pass transistor and one across the output. If you charge up an SLA with one and the line power goes out, or connect a voltage source to it by accident the wrong way, you'll need to buy new pass transistor and driver. Also the push button switches on the E series wear out. Otherwise they're really nice. I use an E30/2 as a radio supply occasionally for low power stuff that is tested and doesn't need current limiting.
 

Offline max_torque

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Re: Power supply advice please (I live in the UK)
« Reply #19 on: December 07, 2018, 02:38:24 pm »
my 10 pence:

Don't skimp or DIY it on the essentials if you really want to get projects finished.

If you are just interested in electronics, and having a project is just a means to that end, then sure, you can make your own power supply or whatever,from kits, or modified existing things (like server PSUs etc).  But, if you actually want to get on with a specific project, then what you need is bench equipment that just works, and that you don't need to spend ages messing around with.

Thanks to china, that no longer means spending ££££.. I started with a 30V 10A Chinese power supply, a cheap Chinese hot air gun and soldering iron, and well, that was it.  I bought a decent (ish) beginner scope (rigol) and got stuck in!

It's easy to see say £300 on a scope be a "lot of money" but how much do you value your time.  Even if you are not producing things for sale, ime, when you are doing projects, even for your own benefit, you want to be spending your time making that project work, and not on making your toolset work.......  :bullshit:
 

Offline CJay

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Re: Power supply advice please (I live in the UK)
« Reply #20 on: December 07, 2018, 02:53:54 pm »
Warning on the Farnell supplies. The E/LT ones are missing a couple of essential diodes, one across the pass transistor and one across the output. If you charge up an SLA with one and the line power goes out, or connect a voltage source to it by accident the wrong way, you'll need to buy new pass transistor and driver. Also the push button switches on the E series wear out. Otherwise they're really nice. I use an E30/2 as a radio supply occasionally for low power stuff that is tested and doesn't need current limiting.

Hehe, I found that one out the hard way :)
 

Offline bd139

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Re: Power supply advice please (I live in the UK)
« Reply #21 on: December 07, 2018, 04:34:02 pm »
Me too :-DD
 

Online nfmax

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Re: Power supply advice please (I live in the UK)
« Reply #22 on: December 07, 2018, 05:06:34 pm »
Warning on the Farnell supplies. The E/LT ones are missing a couple of essential diodes, one across the pass transistor and one across the output.

That's odd - are you sure? I have a couple of these, one L30-1 and one LT30-1. The circuit diagram, issued 1979-07-28, shows 1N4003's in both places, D202 & D203. Maybe it was missing in earlier incarnations of the design? Mind you, a 1A diode is a bit wimpy for a 1A supply, especially when they use two paralleled 2N3055's as pass transistors.

Nice supplies, and the only ones I have at present that go up to 30V.
 

Offline cdev

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Re: Power supply advice please (I live in the UK)
« Reply #23 on: December 07, 2018, 05:11:27 pm »
If you live in the UK, I would seriously consider looking - no making it your goal to buy one of the better UK made power supply brands (like TTI or Thurlby/Thandar) used.

If you do your research you'll get a much better supply value than one you buy new, one that would likely be built to last.

Also, being in the UK a similar situation likely exists to the situation here for US equipment, there is more of it on the used market there, so perhaps a bit cheaper.
« Last Edit: December 07, 2018, 05:15:52 pm by cdev »
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Offline james_s

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Re: Power supply advice please (I live in the UK)
« Reply #24 on: December 07, 2018, 05:40:05 pm »
Used is definitely a good route for power supplies, I've built most of mine, but the commercial units I have I got used.

That leads into another point, if you keep at this electronics stuff you will likely accumulate multiple power supplies, so don't worry too much about trying to find the end-all, be-all PSU right off the bat.
 


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