W1209 module with 5V
scientistnobee opened this issue · 5 comments
Hi, I would like to make a small heat pad with 5V battery powerbank using W1209. However, all I found is 12 V modules. The 5V modules advertised in ebay/Aliexpress don't seem to have genuine parts. Could you please advise me how to get the genuine 5V module or how to convert a 12V module into a 5V module. I have seen a similar question in electronics stack exchange, but there is no satisfactory answer is given, particularly about MOSFET and relay.
https://electronics.stackexchange.com/questions/544292/can-w1209-be-run-with-5v-dc-only
I had a look at the infos on stackexchange:
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when the USB powerpack supply voltage is in the 4.5 to 5.5V range connecting the anode of D2 to the output of the 5V regulator should work.
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After removing the 12V relay soldering a through-hole STP36NF06L at the same spot should work. It's maybe necessary to remove R7 so that the STM8S003 pin10 (PA3) doesn't get any additional load.
Thanks for your prompt reply. Is it okay to short input and output of the 12V regulator? Is there any link where I can buy genuine boards?
I think that shorting in and out should be OK. The thing I proposed would result in a slightly higher supply voltage.
Genuine boards have become as rare as hen's teeth. I asked several vendors but the supply side appears to be dead. The last time I got a board with an STM8S003 controller was nearly two years ago. Today it's almost easier to design your own board with KiCad and have JLCPCB assemble it for you.
I did some experiments with the module by just decreasing the supply voltage. I think circuit is working as it is with 5v without any shorting of voltage regulator, except the relay. What I am thinking is can I turn on 12v relay with 5v supply voltage, just by changing 2k resistor at the base of the transistor? Any suggestions?
@scientistnobee I'll first convert this issue into a discussion thread