Hi to everybody
I have this power supply
(see before.pdf)
the output voltage is variable by a resistor ladder and 3 binary thumb wheel switches (contraves).
It can provide very low voltages (below 1,2 volts to nearly 0 volts) as it use a negative reference voltage (see IC1 and IC2).
now I would like to modify this PSU removing the resistor ladder and the switches, and putting a simple potentiometer:
(see after.pdf)
The problem is that the resistor ladder was not linear :
800Kohm to have 0,1 V.
400Kohm to have 1,0 V.
........
2,8Kohm to have 28 V.
And using the potentiometer the output is not linear too...
Anybody as an idea to get a linear variable output using a potentiomenter?
Thanks a lot in advance
Gianni - Italy
I have this power supply
(see before.pdf)
the output voltage is variable by a resistor ladder and 3 binary thumb wheel switches (contraves).
It can provide very low voltages (below 1,2 volts to nearly 0 volts) as it use a negative reference voltage (see IC1 and IC2).
now I would like to modify this PSU removing the resistor ladder and the switches, and putting a simple potentiometer:
(see after.pdf)
The problem is that the resistor ladder was not linear :
800Kohm to have 0,1 V.
400Kohm to have 1,0 V.
........
2,8Kohm to have 28 V.
And using the potentiometer the output is not linear too...
Anybody as an idea to get a linear variable output using a potentiomenter?
Thanks a lot in advance
Gianni - Italy
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