Hello I am trying to simulate a bias circuit in LTspice, but it does not seem to work.
The potentiometer don't have any effect on the negative voltage.
Here is the asc. Can you help me simulate the transformer AC and rectification, the pot that set the negative bias, don't seem to have any effect.
I used 2 resistors as a pot.
Thank you.
The potentiometer don't have any effect on the negative voltage.
Here is the asc. Can you help me simulate the transformer AC and rectification, the pot that set the negative bias, don't seem to have any effect.
I used 2 resistors as a pot.
Thank you.
There is a lot going on in that sim. It wouldn't even run for me.
Try this. I've altered the grounds (made the voltage source floating) and altered the values on the transformer. If you want 230 volt mains remember that LT need the peak voltage entering and not the rms value. So you need 325 volts if that is what you wanted.
Values for the transformer are guesswork. I don't know what voltages you are looking for.
You need to add 'real' diodes and not just the default. MUR460 are OK. You can alter the others.
Try this. I've altered the grounds (made the voltage source floating) and altered the values on the transformer. If you want 230 volt mains remember that LT need the peak voltage entering and not the rms value. So you need 325 volts if that is what you wanted.
Values for the transformer are guesswork. I don't know what voltages you are looking for.
You need to add 'real' diodes and not just the default. MUR460 are OK. You can alter the others.
Attachments
Thank you. Yes it is heavy...
I am looking to simulate a negative bias voltage, from a 100VAC secondary. It will be used to bias kt66 and 6L6.
I need to find a good range that is why I tried to simulate it. But when I alter the values from the 2 resistors forming the pot, the negative voltage stays almost the same.
I will try with other Diodes.
I am looking to simulate a negative bias voltage, from a 100VAC secondary. It will be used to bias kt66 and 6L6.
I need to find a good range that is why I tried to simulate it. But when I alter the values from the 2 resistors forming the pot, the negative voltage stays almost the same.
I will try with other Diodes.
If it is for a bias supply then you need very little current. The resistors you have draw quite a lot.
There is an error in the earlier sim I attached. One of the MUR460's I changed is wrong (top right diode in the bridge) and is actually marked as the reference number of the diode while still leaving it as a default model.
Try this. 100 volt secondary and around -60v bias voltage.
There is an error in the earlier sim I attached. One of the MUR460's I changed is wrong (top right diode in the bridge) and is actually marked as the reference number of the diode while still leaving it as a default model.
Try this. 100 volt secondary and around -60v bias voltage.
