This is my 3rd version of the programmable laboratory power supply using the best of the two ancestors and adding more power to it:
- 24V 3.3A medical power supply as power source
- 0 ... 20V adjustable output voltage
- 0 ... 3A of adjustable current limitation
- 0 ... 3A of adjustable internal DC electronic load (current sinking on LT3083)
- additional DCDC converters for 3.3V and 5.0V outputs with separate current monitoring up to 1A
- internal switchable step-down DC/DC converter to reduce linear power loss on the LT3083
- SPI TFT with resistive touch- ATxmega128A3U in TQFP-64 package (more memory & more GPIO)
- UART interface to external PC for remote control and data logging
- Bluetooth LE module as alternative wireless control and logging interface (SiLabs/BlueGiga BLE112 module)
- keep it as small and compact as the other two versions (jsLabPS & jsLabPS2), in TEKO KL22 housing
- BOM cost of all PCB components about 84 €, plus 17 € for the PCB itself
- total final BOM cost (all incl., like TFT, heat sink, housing, Fans, power supply, 4mm bananas, main switch & cord) of about 179 € (~ 190 $)
- Printed Circuit Board, just 2-layers, Eurocircuits, Rev B feb 2017 (Rev A assembled & fully tested in Jan 2017, FW fully functional incl. BLE send & receive)
Update 18th of Mars 2017: PCBs of revision B have been received, assembly is just finished, 99% is immediately working, it's mainly calibration what needs to be done yet.
Some small things still need to be reworked or corrected for a next version: the holes for the two DCDC converters (3.3V & 5V) are a bit too small, need to be > 0.9 mm, the two vias near inductor L1 are still too near, so that L1 must be mounted slightly turned to avoid short cuts to these vias, C50 is still a bit too near to CN6, and finally for some resistors and capacitors the footprints are ok for the reflow process but a bit limit for manual soldering, but it works anyway.
Update 21th of Mars 2017: Rev C with corrections for VSYS1 Min Load circuit schema, L1 vias pos changed, C50 pos changed, DCDC hole sizes enlarged to 1mm
Update 12th of April 2017: Rev C with additional (manual) modification for (spare) OPAmp improved I-LOAD measurement
Update 25th of April 2017: added attachments (Atmel Studio HEX file of MCU FW version 1.01, BLE Config Project, BOM with Supplier Links)
Update 21st of July 2017: added attachment (Atmel Studio HEX file of MCU FW version 1.03, additional display photos with different menus and big value variants)
Update 22nd of Nov 2017: added attachment (Atmel Studio HEX file of MCU FW version 1.04, following FW bugfixes/improvements:
- FANs start also if output is NOT on (if the device is connected to a battery with DC-Load=On for discharging the FANs didn't start, because output wasn't active)
- DC-load cut-off-voltage is now shown with 2 digits before the comma (before you could adjust but you couln'd see values > 9.99V)
- better visibility if DC-Load is ON or not (before just the DC-Load values foreground color changed, now the whole rectangle behind changes its color)
PS: a tiny REX (return of experience) information: Rx5 for 5V minimal load is on the limit and always hot (110R 5V 45mA 227mW), better two 220R in parallel :)
Update of April 2020: it's 2.5 years now, that I'm using one at work and two at home on a daily basis and they are doing their job absolutely fine and reliable :)
Update of Oct 2020: just saw an erreur in this text and corrected it - it's the LT3083 circuit of course (not the LTC...), otherwise still happy with it ...
Update of Feb 2021: added attachment I just added a tiny manual how to use the device (I was asked for a video, but decided for a small manual with some explanations)
- Active Participants
Are you sure you want to delete this Release?
This action cannot be undone.
Unable to download from CircuitMaker
You cannot download files inside CircuitMaker.
Please, open this page in browser and download file from there.
To copy hyperlink, press Ctrl+C with selected text below: