On Sat, Jan 21, 2017 at 11:33 PM, Adrian Graham <[email protected]> wrote: > On 21/01/2017 21:59, "Tony Duell" <[email protected]> wrote: > >> On Sat, Jan 21, 2017 at 8:43 PM, Adrian Graham >> <[email protected]> wrote: >>> Hi folks, >>> >>> Does anyone know what this is? It's obviously a transformer coil(s) but >>> image search and googling those markings produces nothing: >>> >>> http://www.binarydinosaurs.co.uk/la4543.jpg >> >> I think the LA number is the number for the ferrite 'pot core' not the >> complete transformer. >> >> It looks to be part of a switching regulator circuit. Possibly to generate >> other voltages from the 5V line. Can you post a picture of more of the PCB >> around it. > > Its second output goes via an IN4148 to the -24V regulator:
What do you mean by 'second output'? How many pins are used on this 'transformer'? If only 2 it is just a simple inductor, again possibly part of a swtiching regulator. > > http://www.binarydinosaurs.co.uk/STCExecutelPowerRegulation.jpg > > The top black wire is from the PSU and goes left-right (in pairs) GND, +5, > +12, -12. I'd do an underside pic too but the board's covered in analyser > wires at the mo. > > The -24V regulator can be seen just above the 4 blue caps, The regulator > that can be seen under the black wire is a 7812. The LF351N has -12V present > at its bias outputs, the opamp to its right has no markings helpfully. What about that IRF523? That is a power MOSFET transistor and might well be the chopper in the switching regulator circuit. Why do you assume the other 8 pin IC is an op-amp? -tony
