How can you milk a cow, while it's sitting on a one legged stool? :)
I never milked a cow, even though I spent time on farms. My grandfather didn't think little kids should be in the barn, till they were old enough to strip tobacco. I did some of the other chores, though.
Or just drop it on someone's head to stun them.
Also how to tell you have a "digital" transistor in front of you?
On a sunny day (Fri, 1 Feb 2013 10:42:07 -0000) it happened "N_Cook" wrote in :
WTF is a 'digital transistor'?????????????????
is,
beyond
aproblems
go
Exactly, thats how they are referred to in UK listings, and without any " "s
On a sunny day (Fri, 1 Feb 2013 11:36:40 -0000) it happened "N_Cook" wrote in :
Well, cannot help you there, but a transistor is a transistor, no matter what is written on - or about it. A rose is a rose by any other name (to keep it UK related).
If my stools had legs I'd be off to the doctor very quickly.
Transistor with base resistor(s) built in. Eg.
Best regards, Spehro Pefhany
On a sunny day (Fri, 01 Feb 2013 08:06:21 -0500) it happened Spehro Pefhany wrote in :
OK, but that is actually an integrated circuit. Just mis-labeled 'transistor'. :-)
You can still test those with a multimeter and lab supply. On a curve tracer for transistors it would look strange I'd guess.
If you see reverse conductance in base emitter junction with an Ohm meter, that would be an indictation. If that resistance was the same both ways, more so.
I'd probably toss it :-)
On a sunny day (Fri, 01 Feb 2013 13:17:42 GMT) it happened Jan Panteltje wrote in :
PS, some of us here will remember RTL logic. That was pretty much like that, but more transistors to make gates, and output R too. Integrated circuits.
You'd have to walk. You'd never be able to sit in your car. ;-)
Its a regular transistor with built in resistors - some are exactly described that way rather than "digital", the most common arrangement is a B-E bleed resistor + a base series current limiting resistor.
They are often used directly as an open collector inverter gate.
My first job was component level fault finding on Olympia desk calculators, they contained about 4 boards of DTL - a 5th board at the back was critically sensitive MOS shift registers. The boards were about the same area as S100, but wider & not so high, the front board had about a dozen nixie tubes.
I must've just missed out on RTL by not all that long, it was only just becoming scarce in component catalogues of the day.
Any idea what $169 is converted to GBP?
Ian Field Inscribed thus:
Just over £105.00p
On a sunny day (Fri, 1 Feb 2013 16:46:09 -0000) it happened "Ian Field" wrote in :
Thanks. Spehro even gave a link to a datasheet.
On a sunny day (Fri, 1 Feb 2013 16:55:24 -0000) it happened "Ian Field" wrote in :
DTL was better, it was faster too IIRC.
Its just a little steep for me - but I have decided I want one.
IIRC the crystal was 3MHz, I assume they'd run the MOS shift registers as fast as they could get away with - and that would probably be what set the upper limit.
One shift register recirculated the product of calculations past a row of TTL 7475s which latched the "correct answer" every time it whizzed past.
I think the BCD to Nixie decoder/drivers were also TTL, the bulk of the chips (over 200) were DTL.
On a sunny day (Fri, 1 Feb 2013 18:40:50 -0000) it happened "Ian Field" wrote in :
In the late sixties or maybe very early seventies I build a frequency counter with 4790 decade counters, and 7475 latches, cannot remember the number of the nixie driver chips, also TTL. It had a 100 kHz crystal as reference, 5 digits, counted up to about 30 MHz, as that was the maximum where the TTL would still work.
Have something to add? Share your thoughts — no account required.
Ask the community — no account required