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91
And a fraction of the size of the biggest ships today, which currently top out at 24,000 TEU!
That's twelve thousand large truck's worth! Yowsers!
92
Dodgy Technology / Re: Ecology vs Disposable Electronic Cigarette
« Last post by themadhippy on Today at 11:48:00 am »
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3 Billion? Not even close:

your right,from the nhs own figures ,not some vested interest group,but the actual people who pick up the bill

Quote
It is estimated that smoking has cost the NHS in England £2.6 billion per year
.
93
It is marked as T6CO1...
I can't find what T6 means. I know that it is type of cable, but I wold like to know more...
94
Beginners / Re: Help identifying some (likely older) compontents.
« Last post by wraper on Today at 11:41:14 am »
Those metal can resistors should be worth something. Especially 0.001% one. Most likely some high stability stuff, although I could not find documentation on quick googling. The rest is pretty much junk.
95
Ahh .. young Yearling. Is that his dad?

I haven't watched enough of his video to know these details.
96
3. use the clock signal to drive a switching circuit, built from MOSFETs or an analog multiplexer. The switching circuit would "chop" a continuous voltage (which is easy to adjust) thus the output level would be adjustable. Problem: I haven't find yet an analog multiplexer fast enough with a small parasitic resistance. Maybe the discrete MOSFET solution would be enough (did some quick simulation tests with a 2N7002A with promising results ... but I need to have a P-channel complementary to have a true switch).

Instead of MOSFETs and voltage switching, use bipolar transistors and current switching, or fast diodes and current switching.  The output level is then set by the easy to control DC current source driving the emitters of the differential pair, or driving the diodes.

97
Beginners / NPN vs N-channel MOSFET for simple low-speed digital switch?
« Last post by Saimoun on Today at 11:39:43 am »
Hi :)

I have a very simple circuit with a 3.3 MCU switching a 5V output. It's low speed (<1kHz) and low current (<50mA).

Is there any advantage of using an N-channel Mosfet over an NPN transistor?
If so, which N-channel would you recommend? I notice that some n-channel I found (for ex the 2N7002) have a Vgs threshold of 2.5V (max value), would it be a problem to drive this with a 3.3V MCU?

Thank you :)
98
Metrology / Re: Null Detector based on Conrad Hoffman design check
« Last post by hozone on Today at 11:32:30 am »
Thanks!

For the low voltage detector I'm moving to MX810, the one with 4.6V threshold, and I'll put it after the LDO. I've worked with MAX809 before (for other purpose), they work good. Do you think it will be ok even there?

I've notice the peak detection in your circuit changes regarding the led used, and op amp used. Find my asm attached. I've to check my design with LTspice too. For my purpose I think there will not be many blinking.
99
General Technical Chat / Re: Custom "R-core" transformers on ebay
« Last post by Zero999 on Today at 11:31:16 am »
Hi squibby,
 
thank you for pointing it out.

Is there any data given for breakdown-voltage / isolation?
Or can you perform an isolation-test primary to secondary?

In the old days Block had transformer-kits with the finished primary winding for 220Volts.

Best regards
Going by the pictures, there are two bobbins. Assuming the primary and secondary are on separate bobbins, then it should have excellent separation, so it seems pointless conducting any insulation tests.
100
Beginners / Re: Help identifying some (likely older) compontents.
« Last post by Traceless on Today at 11:28:30 am »
Thanks to everyone for the awesome help.

     nice resistors, but probably adictive - so send them to me. ;-)))
   Would like to know the manufacturer.

I have quite a bunch of those resistors. Some have odd values (817Ohm, 1.91kOhm) and some surprisingly low tolerances. The best one is 10kOhm 0.001%).  Here is a picture of the entire set. For reference I added a ruler and a 7W power resistor. I'm not sure about the vendor all have that trinagle with an Ohm symbol inside maybe that is the manufacturer logo? I'm also not sure what "Rdm" stands for.

I found a post in a german forum where somone posted pictures of similar resistors. Someone there stated that those were "high temperature, low drift resistors for radar".

2087615-0

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