tribi9 wrote:I got 2 resistors in series that total 10K. I will swap those for the 22K voltage divider to increase the negative voltage then.
If you decrease the 22k, more of the negative bias voltage will 'bleed' to ground, reducing the overall amount of -ve voltage for the bias supply. (-ve voltage is still potential voltage, its just negative instead of positive. It 'acts' the same way as positive voltage and if you want to increase the negative voltage at the 'knee' of the divider, you increase the resistance at the knee of the divider.) Therefore you need to increase the size of the 22k to increase the -ve voltage. The best thing is to put a 20k or 50k pot wired as a variable resistor*, in series with the 22k. That way you can increase the -ve voltage at the turn of the pot
* i.e.; a pot wired with the wiper going to the 22k resistor and one of the pot's end lugs becoming the new 'knee' of the divider i.e.: put the pot between the 22k resistor and the bias supply. Also wire the wiper of the pot to one of the pot's end lugs - that way if the wiper contact fails, the bias supply won't go open
tribi9 wrote:I got 2 resistors in series that total 10K. I will swap those for the 22K voltage divider to increase the negative voltage then.
If you decrease the 22k, more of the negative bias voltage will 'bleed' to ground, reducing the overall amount of -ve voltage for the bias supply. (-ve voltage is still potential voltage, its just negative instead of positive. It 'acts' the same way as positive voltage and if you want to increase the negative voltage at the 'knee' of the divider, you increase the resistance at the knee of the divider.) Therefore you need to increase the size of the 22k to increase the -ve voltage. The best thing is to put a 20k or 50k pot wired as a variable resistor*, in series with the 22k. That way you can increase the -ve voltage at the turn of the pot
* i.e.; a pot wired with the wiper going to the 22k resistor and one of the pot's end lugs becoming the new 'knee' of the divider i.e.: put the pot between the 22k resistor and the bias supply. Also wire the wiper of the pot to one of the pot's end lugs - that way if the wiper contact fails, the bias supply won't go open
