Re: Android
Posted: 11 Feb 2021, 18:30
Put F1 to GND and see if you have +12V on F2 - this should be safe.
If it doesn't work then F1 might need +12V signal to activate F2... if F1 is for something else, then putting +12V on it might kill your device!!! .. but this is how it should work, being made for automotive usage where "back signal" is taken from +12V that goes to backing lights.
If you have a resistor of about 1k -1.2k ohms then you could try to apply +12V to F1 through this resistor:
+12V]--.....--(resistor)--.....--[F1
This way the current (Amps) will be limited to 12-15mA (for +12V to +15V power @1kohm resistor) - https://www.rapidtables.com/calc/electr ... lator.html .. and let's hope that it will be enough to be detected and so you'll have +12V at F2, but still low enough not to damage something if F1 is for something else. Safety first!
If it doesn't work with 1k ohm resistor you can put 100ohm resistor and this will allow max 120-150mA to flow through it .. still a small amount of current, but depending on how your device is made, can still break something :/
This 100ohm shouldn't be touched by hands if connected, as if it is of a smaller power (W) as 0.5W it will get very hot very fast! Usually for a 120-150mA current drain it should be a 2.5 - 3W resistor, but you're just making a test now, so a 0.5W one should be OK.
If it doesn't work then F1 might need +12V signal to activate F2... if F1 is for something else, then putting +12V on it might kill your device!!! .. but this is how it should work, being made for automotive usage where "back signal" is taken from +12V that goes to backing lights.
If you have a resistor of about 1k -1.2k ohms then you could try to apply +12V to F1 through this resistor:
+12V]--.....--(resistor)--.....--[F1
This way the current (Amps) will be limited to 12-15mA (for +12V to +15V power @1kohm resistor) - https://www.rapidtables.com/calc/electr ... lator.html .. and let's hope that it will be enough to be detected and so you'll have +12V at F2, but still low enough not to damage something if F1 is for something else. Safety first!
If it doesn't work with 1k ohm resistor you can put 100ohm resistor and this will allow max 120-150mA to flow through it .. still a small amount of current, but depending on how your device is made, can still break something :/
This 100ohm shouldn't be touched by hands if connected, as if it is of a smaller power (W) as 0.5W it will get very hot very fast! Usually for a 120-150mA current drain it should be a 2.5 - 3W resistor, but you're just making a test now, so a 0.5W one should be OK.
anyway, thanks for help!!