Author Topic: EEVblog #555 - 555 Timer Kit  (Read 34186 times)

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Offline VK3DRB

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Re: EEVblog #555 - 555 Timer Kit
« Reply #75 on: December 15, 2013, 01:52:21 am »
Thanks for the EEVBLOG! The kit could be made mandatory in all high schools. Sure beats reading Shakespeare. You never know we might even become a "knowledge nation" one day.

A few comments if I may...

THE SIDE CUTTERS:

The side cutters look pretty average. I hate having to use crappy side cutters. Every place I have worked at I have reached out to unbelievers and witnessed born again conversion to the TRONEX brand of side cutters. These are a godsend to electronics engineers, technicians and hobbyists. They are of vastly superior quality. They seem to last forever providing you don't cut nails with them. (They do work well on fingernails though!). Mektronics sells a variety of these side cutters, sometimes on special. My favourite is the Tronex 7111 side cutters for general PCB work. If I recall they sell for around $60 or so but will last a lifetime. And no, I don't work for Mektronics.

BLACK PCBs:

Black PCB's look sexy and might even attract chicks. I recently followed one of Dave's EEVBLOG suggestions with a company in NZ called Circuit Labs and got a 4 layered complex board done in matt black. Like with Dave's experience the quality was outstanding, the price cheap and the turnaround time very quick. The reason I got black was the board was used in an optics application and light reflection has to be minimised. Thanks for the tip Dave! I also found it to be very hard to trace PCB tracks visually, but they do look sexy.

The 555:

As for the 555, about 25 years ago some of the bipolar 555's from one manufacturer (not CMOS) were quite noisy. I suspected this was because the the totem pole output transistors could both turn on at the same time creating a very brief short from rail to ground. They were also not very reliable. Since then, if I have used these devices I use the CMOS variety.

Finally, other ubiquitous nostalgic parts besides the '555 include the BC547, LM317, 7805. And let's not forget the 2N3055 and his best mate the MJE2955.
 
cheers,
another Dave.



 

Online notsob

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Re: EEVblog #555 - 555 Timer Kit
« Reply #76 on: December 15, 2013, 02:54:20 am »
If you read page 11-5 of 'designing analogue chips' by Hans Camenzind- he mentions this limitation in his original 555 design, and goes on to show how he would have designed it later in his life [ new design has approx twice the transistors in it ]

Cheers
 

Offline mrkev

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Re: EEVblog #555 - 555 Timer Kit
« Reply #77 on: December 15, 2013, 07:08:37 pm »
I would like to see some measurments on those differential amplifiers and current mirrors.
There is a reason why you won't see those very often in descrete designs, matched pairs on chip can be very precise, but when using descete parts, the VA char. and h21e for each transistor (especially in quad) can be really off.
 

Offline ben_r_

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Re: EEVblog #555 - 555 Timer Kit
« Reply #78 on: December 15, 2013, 07:25:35 pm »
I would like to see some measurments on those differential amplifiers and current mirrors.
There is a reason why you won't see those very often in descrete designs, matched pairs on chip can be very precise, but when using descete parts, the VA char. and h21e for each transistor (especially in quad) can be really off.
LOL its a fancy soldering kit man, not a precision replica...
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Offline Stonent

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Re: EEVblog #555 - 555 Timer Kit
« Reply #79 on: December 15, 2013, 10:08:22 pm »
I suppose you could check the HFE on each transistor with a transistor checker and try to match them that way.
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Offline mrkev

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Re: EEVblog #555 - 555 Timer Kit
« Reply #80 on: December 15, 2013, 10:51:47 pm »
I suppose you could check the HFE on each transistor with a transistor checker and try to match them that way.
Well It's more about the shape of V-A characteristic than h21e. But I was just curious what can you get from discrete solution...
 

Offline SArepairman

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Re: EEVblog #555 - 555 Timer Kit
« Reply #81 on: December 16, 2013, 11:42:20 pm »
I think the trace wiring is beautiful, just looking at some wiring inspires curiosity. I got heated because I saw something that was one solder mask away from being beautiful, its like frustrating you know. It's like you built an awesome dinosaur skeleton and then you decided to throw a garbage bag over it, with the interests of teaching anatomy!!!!!!!!

I could probobly tell you how a 555 timer works, but I know that if I wanted this "geek prop", especially to show others, it would be much cooler to have wiring.

Even if someone does not know alot about electronics you can tell them "oh you see this little thing here with this wire going to it? well yea, that thing is pretty much just like a like this, when it sees something here then it lets electricity through here and...."

I just don't see why it was done.

Its just so much better to see the actual wiring then look at a schematic. It feels so much more real to see that little electrical connection then to look at a boring ass black and white document and believe that it is there.

I don't think things should be made into black boxes unless they absolutely have to be.

Hi,

Quote
I think that kit is trash!
Why so heated up?
It is made to look like a Chip. Therefore black color is essential.

I think it looks nice, and the stuff isn't that complicated... the schematics are sufficient.

If you want such a thing as "training", build it on a breadbord or free-flying-solder w. GND-Plane. The kit is a nice geek-gimmick, but otherwise quite useless ;)
« Last Edit: December 16, 2013, 11:48:34 pm by SArepairman »
 

Offline c4757p

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Re: EEVblog #555 - 555 Timer Kit
« Reply #82 on: December 16, 2013, 11:57:48 pm »
this is WAY too interesting of a detail to miss, its like a picture of a strip tease vs a dildo video.

Yes, I know that when I see a picture of a strip tease, my first thought is "this would be interesting if I could just see the goddamn dildo!"
No longer active here - try the IRC channel if you just can't be without me :)
 

Offline Six_Shooter

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Re: EEVblog #555 - 555 Timer Kit
« Reply #83 on: December 17, 2013, 05:17:15 am »
I think you guys are making too big of a deal over the colour of solder mask.

I like the black, I also like other colours of solder mask. I think a different colour would have been the wrong choice for this kit, simply due to how the finished product was to look. Whens the last time you saw a green or red 555 timer? ;)
 

Offline mrkev

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Re: EEVblog #555 - 555 Timer Kit
« Reply #84 on: December 17, 2013, 07:20:06 pm »
I think you guys are making too big of a deal over the colour of solder mask.

I like the black, I also like other colours of solder mask. I think a different colour would have been the wrong choice for this kit, simply due to how the finished product was to look. Whens the last time you saw a green or red 555 timer? ;)
I don't like any solder mask, wanna keep all my PCBs unmasked  ;)
 

Offline Stonent

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Re: EEVblog #555 - 555 Timer Kit
« Reply #85 on: December 17, 2013, 07:27:45 pm »
I think you guys are making too big of a deal over the colour of solder mask.

I like the black, I also like other colours of solder mask. I think a different colour would have been the wrong choice for this kit, simply due to how the finished product was to look. Whens the last time you saw a green or red 555 timer? ;)
I don't like any solder mask, wanna keep all my PCBs unmasked  ;)

How about making the "foot stool" but have a lid on it that you can flip open to probe it?
The larger the government, the smaller the citizen.
 

Offline ben_r_

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Re: EEVblog #555 - 555 Timer Kit
« Reply #86 on: December 17, 2013, 08:43:36 pm »
I think it looks awesome just the way it is! The flat black soldermask is mean to look like the flat black housing that the real 555 chips come in I think. Either way for what I bought it for, its perfect right on my desk :)
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Offline SArepairman

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Re: EEVblog #555 - 555 Timer Kit
« Reply #87 on: December 18, 2013, 12:03:40 am »
I think you guys are making too big of a deal over the colour of solder mask.

I like the black, I also like other colours of solder mask. I think a different colour would have been the wrong choice for this kit, simply due to how the finished product was to look. Whens the last time you saw a green or red 555 timer? ;)
I don't like any solder mask, wanna keep all my PCBs unmasked  ;)

How about making the "foot stool" but have a lid on it that you can flip open to probe it?

I agree, it should have a black case that looks like the real chip and open up so you can look at the wiring under the hood, preferably with a single sided PCB using jumper wires if necessary.
 

Offline c4757p

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Re: EEVblog #555 - 555 Timer Kit
« Reply #88 on: December 18, 2013, 12:23:12 am »
preferably with a single sided PCB using jumper wires if necessary.

Why?
No longer active here - try the IRC channel if you just can't be without me :)
 

Offline Stonent

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Re: EEVblog #555 - 555 Timer Kit
« Reply #89 on: December 18, 2013, 11:45:30 am »
And just because...  I'd make the legs out of real metal and be live.
The larger the government, the smaller the citizen.
 

Offline SArepairman

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Re: EEVblog #555 - 555 Timer Kit
« Reply #90 on: December 19, 2013, 06:38:10 pm »
preferably with a single sided PCB using jumper wires if necessary.

Why?

so you can see exactly how everything is wired.
ok maybe a ground plane is ok.
 

Offline J4e8a16n

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Re: EEVblog #555 - 555 Timer Kit
« Reply #91 on: May 20, 2017, 06:50:20 pm »
Here are some 555 LTSPICE    files I created.
« Last Edit: May 20, 2017, 11:11:01 pm by J4e8a16n »
Equipment Fluke, PSup..5-30V 3.4A, Owon SDS7102, Victor SGenerator,
Isn't this suppose to be a technical and exact science?
 


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