Without seeing the OTHER side of the PC board, I'm not convinced you have a microphone there.
If it is an electret microphone capsule (with the impedance converting transistor circuit inside) then you must apply power to the microphone to make it work. It is not a passive device that generates voltage.
Without seeing the OTHER side of the PC board, I'm not convinced you have a microphone there.
If it is an electret microphone capsule (with the impedance converting transistor circuit inside) then you must apply power to the microphone to make it work. It is not a passive device that generates voltage.
I did power it. I used a variable PSU and a biasing resistor. I have used electret mic capsules in the past so I have an idea on how they work and how they should behave.
If you're talking about the tiny round PCB with a transistor and two caps on it, the back side is this one.
If you're talking about the flex PCB the device is mounted to, it is just a ground plane.
The part is not much of use for me, just a curiosity on what it really is. What I really want is to ID the LED
I've only got the usual pointless ebay seller's potato picture of the chip
but what is a "MOSTEK MK3884N IRELAND" ?
searches lead me to
http://www.cpu-world.com/Support/3/38.htmlSo I know it's one of Zilog's SIO's, but I can't work out the speed
MK3884 and MK3884-10 are 2.5 MHz parts.
MK3884-4 is a 4 MHz part.
so what is an MK3884N ?
thanks
so what is an MK3884N ?
darn, I'd downloaded that same document the other day but didn't notice that line.
I was looking for my download of it this morning but it's lost in one of windows random download locations.
Thanks for finding it for me
Hi,
I have a rather "stealth" chip here. I can't even identify the vendor. The chip should be part of a broadband power line system.
Can anyone identify the manufacturer ? Can anyone find a datasheet?
Thanks
Christopher
What sort of compressed air coupler is this? I can't find it with image search, some sort of PCL knockoff?
My google-fu is not very strong today. DIP8 SMPS controller, it's not the AIC1550 (it's not a DC-DC converter).
It is the first hit on 8107a on the Chinese search engine baidu, it can also be found on aliexpress and taobao.
1550 is likely the datecode. For recent and obscure chips like this it is beneficial to know other branches of fu.
Anyone recognize this one?
It's from a 1988 vintage motor controller, so I'm guessing a triac of some sort.
I can't find anything resembling a datasheet, so finding a replacement is proving more difficult then expected.
Hi guys,
Does this kind of assembly have a specific name? It was used to position optics onto a measurement system.
The ruby tipped probes are called "CMM Stylus"? Or is there another name for them?
Thanks,
David
Anyone recognize this one?
It's from a 1988 vintage motor controller, so I'm guessing a triac of some sort.
I can't find anything resembling a datasheet, so finding a replacement is proving more difficult then expected.
Part is TAG8816, which is a now obsolete Triac from either Siemens or AEG. Most likely a BT132 triac will be a replacement for it, though I will bet that it is driven with a SAA series triac controller, and that, or the capacitors associated with it, is dead.
Thanks!
It is indeed AEG and driven by a
TDA1085C controller.
I suspect, as you said, the controller and surrounding caps where the problem.
But as I don't have the rest of the machine, I'm replacing everything just to be safe.
This unknown ceramic PGA chip comes from a remote control for industrial cranes. Couldn't even find the manufacturer "IST" ?
The remote control dates back to 1994. Had no time to trace the other peripherals on the board. So no idea if the crystal oscillators belongs to the ceramic chip.
I would guess that it is something like a GAL/PAL/PLD? Or even a microcontroller?
Thanks!
It is indeed AEG and driven by a TDA1085C controller.
I suspect, as you said, the controller and surrounding caps where the problem.
But as I don't have the rest of the machine, I'm replacing everything just to be safe.
If the triac died that chip will be toast as well. I have met those before, so also change electrolytic capacitors connected to it, all of them. They are pretty good at speed control, but as the capacitors age the ESR goes high, the chip goes wonky and runs the motor to full speed or runs in bursts. If the motor arcs over then it fries the TRIAC, and this kills both. If the snubber is not there across the triac add it, using a 100R 1W resistor and a 100n 250VAC class X capacitor, if there replace the capacitor as well, using a class X device.
This unknown ceramic PGA chip comes from a remote control for industrial cranes. Couldn't even find the manufacturer "IST" ?
The remote control dates back to 1994. Had no time to trace the other peripherals on the board. So no idea if the crystal oscillators belongs to the ceramic chip.
I would guess that it is something like a GAL/PAL/PLD? Or even a microcontroller?
Custom gate array, so you are SOL unless you can buy one from the manufacturer. However I would look at the clock from that ( likely) CD4001 chip, to see if it is actually oscillating.
This unknown ceramic PGA chip comes from a remote control for industrial cranes. Couldn't even find the manufacturer "IST" ?
The remote control dates back to 1994. Had no time to trace the other peripherals on the board. So no idea if the crystal oscillators belongs to the ceramic chip.
I would guess that it is something like a GAL/PAL/PLD? Or even a microcontroller?
Custom gate array, so you are SOL unless you can buy one from the manufacturer. However I would look at the clock from that ( likely) CD4001 chip, to see if it is actually oscillating.
Thanks for your assessment. There is no need to repair anything. Pulled two of these remote controls out of the dumpster at work. This one from 1994 and another from 1976. Kept four heavy coordinate switches from them. And this chip purely out of curiosity what it would be.
I will decap the chip and try to get some good pictures of it.
The letters 'TH-GAS1' is a strong hint that it is a mask gate array. Photomicrographs are not that interesting, although if you knew the floorplan of the array you may be able to reverse engineer the RTL from the visible metal layer. Many gate arrays were programmed with a single custom metal layer, but I think some used more than one.
I don't know if this is missing any parts, I suspect it might be. But it appears to be some sort of high voltage switching tuby thingy. It is (or was) in a vacuum (or gas), although one of the terminals has internal cracks and I hope it hasn't vented. The contact is magnetic (part of some sort of relay or contactor maybe?).
EDIT: confirmed a vacuum relay of some sort. An image search turned up a pic of a recent Ebay listing for a device with a part similer to this one though. Mine is missing the rest of it including the coil and brackets (although if it hasn't vented I can replace those). But I can't find any other info.
I'm trying to find out what this IC is exactly. It's part of a fan speed controller board.
It's an 8-pin SOIC package, and the only marking on it is 'HXN-JOa' (not sure if that 'O' is actually a zero or not). I have a suspicion it may be some kind of adjustable DC-DC buck converter that is being used to step-down 12V to a lower voltage. Possibly from a Chinese manufacturer, as the only references to the marking text I could find were on Chinese websites.