Thread: Identify IC ?
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N_Cook N_Cook is offline
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Default Identify IC ?

On 11/03/2019 05:44, John Robertson wrote:
On 2019/03/10 2:13 p.m., N_Cook wrote:
On 10/03/2019 18:31, N_Cook wrote:
On 10/03/2019 16:06, N_Cook wrote:
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.


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 :-#)#


The 14A of these EDM

http://www.aga-museum.nl/page/geodimeter-model-12-

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.