RIFAR540 RD6416 N Could be 1 instead of I , and N probably refers to the plastic encapsulation. 14 pin IC in the power supply section of some 1979 kit.
- posted
5 years ago
RIFAR540 RD6416 N Could be 1 instead of I , and N probably refers to the plastic encapsulation. 14 pin IC in the power supply section of some 1979 kit.
Until I can power-up probe/explore trackside, my guess is perhaps , from the "16", a variant of CMOS quad analogue sw.
pins 1,3,5 and 13 seem of the same type or function, inputs or outputs or control lines from another board, so could be quad an. sw. A stepped range of supply volts or amps would make some sense for a step-wise variable drive.
79 kit.
om
UA/LM741 was a common regulator back then and came in a 14 pin DIP, but it doesn't match your description of particular pins. Where is your device relative to the pass transistor? Does it drive the base or the [ass transistor or does it drive another transistor that perhaps drives the base?
What equipment is it used in? You say some kit, more info may help if one of us has the schematics...
John :-#)#
-- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd.
** Huh ??
Surely you mean the uA/LM723 adjustable regulator.
The LM741 is a most famous op-amp.
... Phil
The 14A of these EDM
The external V reg for 12V car battery down to 6V failed decades ago , repairing that, there was still a fault inside. Powering up these days all the amber nixie segments light on test, signal LEDs light , servo neutral density filter rotates, a shutter moves but no cue tone on the audio and simple IR phototransistor+red LED zapper tester shows no IR output. Getting inside and isolating (perhaps, not wanting to disturb the fixing of the sub-board in its screened box as all optically aligned) the Tx GaAs diode cold tests as likely functional. Next thing (as 4 densely packed boards of TTL and CMOS and rather too many "after-thought"/mod flying components including a 14 pin IC) is fit back together , expanded with standoffs, to be able to probe the PS area. But stepped supply to the Tx diode makes operational sense. The only tech material i've found is this general principles of operation of such EDM of that time. It has some provenance, owned by Ordnance Survey the premier map-makers in the UK, until something went wrong with it and they entered it into one of their then regular auctions of surplus stuff.
omission
Harris semiconductor had a series run in 70s of RD*** and did loads of an sw variants in 80s/90s, perhaps RD6416. There is certainly 4 "channels" associated with it , a resistor different values , BC107 pre-driver and a TO220 driver/pass transistor repeated 4 times.
Thanks Phil, of course I meant the 723. That is why you should never post after an evening of wine...
John :-#(#
** Back in the early 1970s, I put together a bench PSU for myself using an LM723 plus 2N3055 pass transistor.
The 723 was in the then common TO100 round, gold lead pak.
I still have and use the PSU.
With the addition of a few upgrades, it does 2.2 to 20V at 2 amps with continuously variable current limit from 100mA up.
.... Phil
But then, where's all the fun?
OT:
An evening of wine and Midsomer Murders is the usual fun for a couple of evenings a week with my wife...
John :-#)#
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