9 thoughts on “Voltlog #39 – 60W Dummy Load Reverse Engineering”

  1. Hello,
    I have disassembled and photographed the display board to do so.
    The data transmission to the display is via SPI bus. The display 2 piece TM1650 are used as drivers.
    If you (also translucent via Photoshop) would like the photos, send an email to: old-Papa@web.de


  2. Could you find where does pin 26 of the chip connects?. It would be the more reasonable choice pin if the free ports L and/or F are for SWIN (DATA) connexion with a ST-Link programmer. However, as far as I found from your excellent work, L seems to be connected to pin 32 (TIM1_CH4 [AFR4]) and F to pin 27 (TIM1_CH3 [AFR3]).

  3. Thanks for your prompt reply. I couldn’t see the programming header. Pin 1 seems connected as well to Pin 32, isn’t it?. Then this ‘L’ would be the NRESET pin. If so it would make sense that a SWIM connector from a ST-LINK/V2 programmer (20 EUR) can be connected to the programming header you mentioned and the Reset pin to L (Vc and G are obvious). It would be great to fully reverse engineer the electronic load making open source code for it… maybe can be made to work by software in Constant Voltage or Constant Resistance mode. Of course all this would require knowledge of the STM-Studio or IAR programming environments.

  4. My ZPB30A1 is off in current ratring by about 100mA. If I set the load to sink 1A it really draws 900mA. Is there a way to adjust this deviation?

    Perhaps by twiddling with R37 in your schematic (MOS-FET Gate resistor)?

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