AY1-5051 datasheet or pinout please?

has

repair

I don't have 5051 data or items but the AY1-5050 is PCH technology , whatever that is. with for 14 pin DIL ground pin 1 ,Vdd pin 8 and Vgg pin 14 The rest would be tracing which goes to which octave and inferring

I have a couple of salvaged 1978 , 5050 in front of me with pinning, no knowledge if working order. With a DVM diode test and -ve to ground pin one measures .71 to Vgg and .66 to Vdd pin other is .8 and .74V

for isolated dividers with no internal linking and a few readings referred to pin 1 as -ve to pin labelled input .88 and its o/p .78 and some others .95 i/p and .86 o/p ,97 and .85V o/p those with internal linking are nearer the o/p readings, up and down

• probe to pin 1 ground then no forward drop reading to any other pin , max 2V IIRC on Fluke 77

Please report back any findings on the 5051 pinning , voltages etc, for the archives.

Early Maplin in UK catalogues had pinning etc for a number of AY1- organ use series

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

has

repair

I assume you have some voltage on the power rails and at least 1 pin has some oscillation signal on it.

If you can determine which the DC rail pins are I can check 4 other pinouts that are probably GI AY1- ???? frequency divider ICs but no cross-reference back to the IC numbers, but they all have different DC rail pins than the

Whether isolated , 2 or 3 interlinked then all related pins to one divider chain are on one side of the IC, none cross over to the other side.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

Don't know if this helps or not but apparently this was made by General Semiconductor, later acquired by Vishay

Fresh off the scanner, all two pages of it. (about 50k bytes).

Includes AY-1-5050 AY-1-5051 AY-1-6721/5 AY-1-6721/6

Mark Zenier snipped-for-privacy@eskimo.com Googleproofaddress(account:mzenier provider:eskimo domain:com)

has

repair

Thats tidied up the mystery of the graphics only sheet I have from GI as only the 5050 was labelled as such.

The next problem is how to buffer the outputs of a 4024, or something, to drive 30V chippery? a 4104 is not high enough , 7x discrete SM ?

So to the OP - what are the next devices in the chain being driven by each octave from the ay1-5051 ?

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

The sort of task I would relish doing, now realised its only 3 octaves This is how I'd tackle it assuming enough spare space

Wire a chopped down to 10 pin turned pin socket to the pcb and glue in place. Another chopped down socket , to plug into the first, wired to a piece of matrix board. Try an "upside down" ,positive ground (is that possible?) 4024 between Vdd and ground and voltage divided input signal to one of the 4024 inputs and and try just one output , level shifted with transistor and a couple of Rs , from Vgg, to drive any high level tone generators or whatever comes after.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

^ Note: You guys might have better luck adding in the extra "-" in the part number for your searches.

Did you see the fine print about the two power supplies. The outputs are fed seperatly from VDD, which only goes to -13 volts. And that VDD can be modulated for various effects. Using the numbers in the "Drive capablity" section of the characteristics, it looks like the output is a Fet pulldown with a 6k ohm load.

Here's how I would do a workalike.

Power supply. You have to use the -27 volt VGG since VDD can be modulated. So a 12 volt or thereabouts zener, and a series resistor should be ok to get a -12 volt supply. Which will feed some CD4000 family chips, running upside down. Their positive power supply being the PMOS ground. Typical drain for the old chip is 3 milliamps, that should be plenty for a handful of CMOS logic running at audio frequencies.

For each input, an input resistor, diode clamps to the CMOS power positive (gnd) and negative supply, and a schmitt trigger buffer or inverter. CD40106? Then use either D latches (4013) or JK ff's (4027) for the dividers. Easier to get the short divider chains than the CD4024 if you don't know how the external circuit is wired. If which edge is the trigger matters, you may needed to chain one of the spare 40106 inverters to get the right polarity to feed the flip flop.

For each output, a small p channel MOSFET, source to (PMOS) ground, with a 6.2k ohm drain resistor to VDD. (Or maybe a jellybean PNP with a base resistor. Depends on the sound that results, perhaps). You might need a capacitor or RC filter across the output to slow down the edges.

Mark Zenier snipped-for-privacy@eskimo.com Googleproofaddress(account:mzenier provider:eskimo domain:com)

Many thanks for the information. I shall be looking at the organ again on Monday and will report back. I much appreciate the effort you guys have put in.

Gerry Wareham Dorset UK.

put

Is it only 3 octaves or would there be 2 of the 5051? for more octaves?

Could you note the model number and any chip datecodes , or dates on capacitors etc

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

Modulus

General

He

each

I followed and agreed down to jellybean ? Translates as general purpose, low f, low V,low A, low power?

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

Sorry. (Two nations seperated by a common language). One for your UK/American translation glossary...

Jellybean = inexpensive and commonly available

Mark Zenier snipped-for-privacy@eskimo.com Googleproofaddress(account:mzenier provider:eskimo domain:com)

Do you have bean-counters over there ?

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

yes, the originals: MBA = 'Masters of Business Annihilation'. :(

Hi,

Well I managed to repair it with you fellows kind help. Much appreciated. It wasn't a faulty AY-1-5051, it just had no VDD supply. I was able to find that out from the scanned data sheet. I then traced the wiring to find, deep in the dust at the bottom of the organ, a power regulator circuit which turned out to be a -10V PSU. This was giving no output at all. A buzz round with my DMM on diode test showed an open circuit base/emitter on an ancient Fairchild BC208. I replaced it with a BC548A and it's now all fine.

Jack, my 82 year old friend is very pleased and reckons he'll be entertaining his family over the holidays - but apparently his wife wants to sabotage it ;-)

He too thanks you for the help and we both wish you all a Happy Christmas.

Cheers, Gerry.