Hi,
I have started designing a very simple, switched mode, benchtop PSU with three separate outputs, based on DPS3005 adjustable power modules. The mains transformer is 120VA with four separate secondary windings: 24VAC@1.3A, 16VAC@2.2A, 16VAC@2.2A and 9VAC@1.1A. The 9VAC winding will be used for any logic needed for relay operation etc. The 9VAC winding might also be used in later state to power a Raspberry Pi Zero W.
Here are the main specs:
- Three separate outputs with 2x12V@2A and 1x20V@1A output which can be connected in series or parallel
- Each output can be enabled/disabled individually (DPS3005 has enable/disable button)
- All the outputs can be enabled/disabled simultaneously by a switch (three relays with SPDT contacts disconnecting the load from the PSU)
- Each output can be programmed to CV or CC mode with voltage and current limit (built-in to DPS3005 by default)
- Each output will provide voltage, current and power display (built-in to DPS3005 by default)
The diode at the output is actually a transient suppressor diode (TVZ) which will clamp any high voltage spikes at the output from inductive loads. The noise suppression is done using simple PI-filters at the DPS3005s inputs and outputs (If I have understood correctly, the DSP3005 will generate some switching noise from its inputs, thus the filtering also at the inputs).
Unfortunately the DPS3005 modules I have at the moment do not contain the serial port control ability, which would have been a very nice addition to the power supply capability. With the serial port control capability one could add a Raspberry Zero W inside the box which would control all three modules and provide some long term measurement statistics etc. any any other scripting ability with WIFI connectivity The three channels and the Raspberry Pi could be isolated very easily with simple opto couplers.
Any comments or suggestions are welcome!
Br,
Kalvin