Dear all as i am a new member please forgive any mistakes.
I am asking help for the following.
I have a 0-300mA qauge with damaged internal resistors.
I have remove them but are burned so no possible to measure values any more.
In order to check the rotating coil i have measure the coil resistance alone, that is 2,28Ohm.
Then i have apply 1,37 dcv from an AA batery and in series i had connect a 100ohm pot, the full scale deflection (300mA) comes when the pot is set at 71 ohm, pot measured after dc voltage removed.
Second measurment i take is again with the circuit operative and FSD adjusted to 300mA as before,
the voltage across gauge terminals was 0,035V.
I would like to connect this mA in my power suply which operates from 400 dcv up to 680 dcv with max load 250 mA.
Can someone please calculate the two resistors i have to connect (shunt and series) and give me an information regarding the wattage also?
Thanks in advance for your help.
Dimis
I am asking help for the following.
I have a 0-300mA qauge with damaged internal resistors.
I have remove them but are burned so no possible to measure values any more.
In order to check the rotating coil i have measure the coil resistance alone, that is 2,28Ohm.
Then i have apply 1,37 dcv from an AA batery and in series i had connect a 100ohm pot, the full scale deflection (300mA) comes when the pot is set at 71 ohm, pot measured after dc voltage removed.
Second measurment i take is again with the circuit operative and FSD adjusted to 300mA as before,
the voltage across gauge terminals was 0,035V.
I would like to connect this mA in my power suply which operates from 400 dcv up to 680 dcv with max load 250 mA.
Can someone please calculate the two resistors i have to connect (shunt and series) and give me an information regarding the wattage also?
Thanks in advance for your help.
Dimis