convert a linear psu to a load?

[ME]

I have an old linear psu for parts, the pass elements are 14x 2n3055 transistors with emiter resistors all mounted on heatsinks , would it be possible to cobble an electronic load from this? , I also have a 150w chinese load kit using fets , could the 2 be combined , Using the 150watt load to control all the 2n3055 transistors as the load, I have a farnell TS-V70 MK2 psu i need to load test.

[RoGeorge]

Aside from modifying the existing schematic so to reuse the power components (which should be possible), there is a way to use any normal power supply as a battery load, so to control the discharge of an external battery with a normal power supply (unmodified), by the idea shown in:  https://www.eevblog.com/forum/projects/cc-cv-power-supply-as-a-contolled-load-for-batteries-(i-e-rigol-dp832)/

Did that for my Rigol DP832 PSU, so to measure the mAh of rechargeable batteries.  Instead of a simple resistor, built this adapter 3 times, once for each channel (DP832 has 3 outputs, there are in fact 3 power supplies in the same box):

More images in this post:  https://www.eevblog.com/forum/projects/cc-cv-power-supply-as-a-contolled-load-for-batteries-(i-e-rigol-dp832)/msg5744693/#msg5744693

[ME]

Thanks for a reply but , This psu can output 100v at ? amps

[factory]

As stated in the thread you created elsewhere, this PSU is intended as either 35V 10A or 70V 5A, anything else will probably end badly.

https://www.vintage-radio.net/forum/showthread.php?t=225016

David

[ME]

Can you explain how your answer answers my original question ? if you dont mind.

[mtwieg]

In general sure, a linear PSU should be able to act as an electronic load by shorting its output to a low resistance (or a short to GND, if the psu had an adjustable current limit). Then the input of the linear PSU would function as the input of the electronic load.

One limitation with this approach is that the minimum load voltage is going to be at least the dropout voltage of the PSU, which will probably be two or three volts at least. If you want to operate at lower voltages, you'll need a more conventional approach.

Also even if the core power stage of the PSU only needs a few volts to operate, the other control circuitry on the PSU might depend on having a higher semi-regulated voltage. You may need to supply that circuitry with a separate smaller power supply.