Hi all,i have a big psu with a big transfo+ 13 pass transistors on heatsinks,the control pcb is u/s so want to make a new one for it,i have a few lm723 ic's and a sg 3532,can anyone point me in the direction of a suitable schematic to use the sg 3532 chip,i would like it adjustable with cc and cv modes,thanks in advance.
TI’s LM3532 is a High efficiency white LED driver with programmable Ambient Light Sensing Capability and I2C Compati. Find parameters, ordering and quality information
You could try something like this, with the output stage modified for higher current; if it works with a 723, you could try dropping in the SG3532 & see if that works OK?
The SG3532 was an improvement over the veritable uA723, and should work with some modifications.
For instance the SG3532 is nominally 2.5 volts, compared to the uA723’s 7.15 volts. The feedback resistors must change.
There are other parametric differences, you have to download both datasheets and make a list of those parameters.
Are you sure there are 13 'pass' transistors, it would be fairly usual to have 12, with the 13th being the driver that feeds them - the gain on 2N3055's is LOW!!!. There would then be a pre-driver feeding the single 2N3055 driver.
Is there any reason you're not just repairing the existing PCB?.
i an not repairing the old pcb as its in realy bad condition+ i want it variable like 0-30v/0-30amps if poss with cc+ cv modes one of the 2n3055 transistors maybe a driver,its not fully apart yet,it has lots of old coroded spade connectors so want to rebuild it using the transistors tranfro rectifier+ my sg 2532 also use 10 turn pots etc.,it looks like its been years in damp storage,its in a mucky terrible state.but could be a good base for a variable high power bench psu.,i am trying to decide on the available options i have using what i have ok.