Aim-TTi LD400P Programmable DC Electronic Load

[Short Circuit]

Here are some pictures of the gut of my new LD400P electronic load from Aim-TTi.
This is a 80V/80A/400W load with 1-minute overload capacity of 600W.

The main reason for buying this baby was it's Constant Conductivity mode.
While very similar to Constant Resistance, the control method is different. This is supposed to prevent oscillations when testing with power sources that operate with current limitation. My old load (a simple TekPower / "eBay") would cause the PSU and load to oscillate, pretty similar to the behaviour described in https://www.eevblog.com/forum/testgear/bk8500-oscillations-in-r-and-p-mode-broken-or-bad-design/msg389066/#msg389066 this thread.

In addition it provides some programmability with A/B levels with can be set to alternate in specific frequency, duty cycle and slew-rate.

[Short Circuit]

The load is build around two SOT-227 power devices mounted on opposite sides of the heatsink tunnel.
Front panel is driven with an LPC2368 controller. There is a second LPC on the I/O board in the back of the device. This seems to connect with the main CPU via an opto-isolated serial interface.
I was somewhat surprised to find an ordinary linear power supply with multiple mains transformers in this device. There is no clue about the design date of this machine (PCB datecodes are 2014), but as far as I know, it hasn't been that long ago that this model replaced their previous load LD300...

[Short Circuit]

And finally the 'real' control board...

[rich]

Nice thanks for sharing. I've been considering whether to build or buy one, so it's good to see inside this TTi version.