What Does This Thing Do?

[EasyGoing1]

I bought a pack of misc electronic things for $5. They said it was a student kit for some classes.. It came with various components and this circuit ... which I can't determine what it does or what it's used for. I tried finding a datasheet for the chip but the closest thing I can find indicates it is a quad op amp but when I work the op amp diagram into the schematic of this circuit it makes no sense.

Attached is the photo of the circuit as well as the schematic I drew up based on what info I could find.

Any ideas?

[PeteS in CA]

Re: What Does This Thing Do?

Well, it does appear to be an Exar quad op-amp. The "7711" date code means it was produced in the 11th week of 1977. From the datasheet, it looks like the performance of the op-amps would be similar to an LM324, but NOT the same pin-out.

I don't know whether this helps make the circuit make any better sense, but pin 1 of the IC is in the bottom left corner as the IC is seen in your picture, not the top left corner. I'm kind of wondering whether it's some sort of assembly or soldering test board rather than a meaningful circuit.

[rievax_60]

Re: What Does This Thing Do?

I don't think it does anything. There are no distinct power input points. I'm confident that the IC is being identified correctly as a quad op amp. so the way the other parts are connected make no sense at all.
It just looks like practice at building a useless circuit.

[EasyGoing1]

Re: What Does This Thing Do?

Well, it does appear to be an Exar quad op-amp. The "7711" date code means it was produced in the 11th week of 1977. From the datasheet, it looks like the performance of the op-amps would be similar to an LM324, but NOT the same pin-out.

Good call on the pinout ... I changed the schematic given the proper pin placement ...

[EasyGoing1]

Re: What Does This Thing Do?

Perhaps it was someone's project, but it received an 'F' ... lol

[petehall347]

Re: What Does This Thing Do?

it wont work properly .the resistors should be all same value ...
it needs more parts to do anything .. maybe it ends up as a touch this bit and a light comes on .. or flashes .
shit the pinouts changed after i posted .. vcc is not in a good place now

[petehall347]

Re: What Does This Thing Do?

4136 ic ....

[EasyGoing1]

Re: What Does This Thing Do?

I forgot to include an image of the backside and some markings that I left out ... they might be relevant???

[stj]

Re: What Does This Thing Do?

it's electrically bullshit.
infact i cant imagine any chip that could hook to transistors like that.

i suspect it's just some random crap made to teach stuffing and soldering.
and on that subject, i give the student an F.
infact it's so bad i'd tell them to get the F out and find another course.

[eccerr0r]

Re: What Does This Thing Do?

Is that IC in a socket? Perhaps someone swapped the IC to confuse us all.

BTW, even if the pinout of that 4136 is the same as the LM324, I would not use the 4136 in a pinch. The characteristics look more like two LM1458's than LM324...

[Spork Schivago]

Re: What Does This Thing Do?

I found a site, esssales.com. I believe they sell various kits from other companies. Maybe the ESS/IEU means ESS sold it, for a company that went by IEU? Maybe the PDC means Practice Development Circuit?

Even though I cannot find the circuit on their site, they do sell practice circuits, for soldering. Maybe if we had some sort of date, we could use he wayback machine and try to figure it out?

[EasyGoing1]

Re: What Does This Thing Do?

Is that IC in a socket? Perhaps someone swapped the IC to confuse us all.

NO, it's soldered onto the board.

[EasyGoing1]

Re: What Does This Thing Do?

I found a site, esssales.com. I believe they sell various kits from other companies. Maybe the ESS/IEU means ESS sold it, for a company that went by IEU? Maybe the PDC means Practice Development Circuit?

Even though I cannot find the circuit on their site, they do sell practice circuits, for soldering. Maybe if we had some sort of date, we could use the wayback machine and try to figure it out?

I could only guess ... sometime within the last 10 years.

Im just going to desolder the components and throw them in the pile.

[EasyGoing1]

Re: What Does This Thing Do?

it's electrically bullshit.
infact i cant imagine any chip that could hook to transistors like that.

i suspect it's just some random crap made to teach stuffing and soldering.
and on that subject, i give the student an F.
infact it's so bad i'd tell them to get the F out and find another course.