Hi,
I'm very new, so please forgive me if I'm not descriptive enough. I'm building a geiger counter from here: https://github.com/pra22/GC-20
It's based around a Wemos D1 mini.
I have my circuit assembled short of the geiger tube (SBM-20 on the circuit diagram). I powered up my circuit and unfortunately my battery polarity was backwards. The solder on the U5 linear regulator immediately melted. After replacing it, I was able to turn it on and programmed my board. I'm supposed to be getting approximately 400v at the positive side of where the SMB-20 connects and I'm only getting a fluctuating voltage between around .5vdc and 1vdc. What could be the issue with my circuit? I've checked the polarity on all the components and they all seem to be correct. The only part I'm unsure about is my 555 timer. It doesn't have the usual notch or indent on it anywhere. It does seem to have a line printed across one end that I've taken to assume is the end with the gnd and and supply voltage
Any help would be appreciated.
I'm very new, so please forgive me if I'm not descriptive enough. I'm building a geiger counter from here: https://github.com/pra22/GC-20
It's based around a Wemos D1 mini.
I have my circuit assembled short of the geiger tube (SBM-20 on the circuit diagram). I powered up my circuit and unfortunately my battery polarity was backwards. The solder on the U5 linear regulator immediately melted. After replacing it, I was able to turn it on and programmed my board. I'm supposed to be getting approximately 400v at the positive side of where the SMB-20 connects and I'm only getting a fluctuating voltage between around .5vdc and 1vdc. What could be the issue with my circuit? I've checked the polarity on all the components and they all seem to be correct. The only part I'm unsure about is my 555 timer. It doesn't have the usual notch or indent on it anywhere. It does seem to have a line printed across one end that I've taken to assume is the end with the gnd and and supply voltage
Any help would be appreciated.