You mean there is no drop over the setting resistor near it? Because with Vgs=4V its certainly on.
yes, there is a drop over the resistor, but only IxR
U is at drain and source the same
I expect a drop in voltage
or not?
U is at drain and source the same
I expect a drop in voltage
or not?
You should have Vin-Vout across the CCS Mosfet. Can you set the output at all by turning the voltage setting trimmer?
just measured
Vin 44v
Vout 43,5v
50mA (0,5v over the 10ohm resistor)
when turning the pot to 100mA
Vin 43,5v
Vout 42,5v
possible mosfet is blown out?
Vin 44v
Vout 43,5v
50mA (0,5v over the 10ohm resistor)
when turning the pot to 100mA
Vin 43,5v
Vout 42,5v
possible mosfet is blown out?
checked
are ok
measured also other channel,same reading
so I can set the mA, but no voltage change
are ok
measured also other channel,same reading
so I can set the mA, but no voltage change
Do both Mosfets show VGS reading? How much is the voltage drop across the series resistor under the trimmer? Is the trimmer correctly wired as a rheostat?
That means there is 6.12mA running in the resistive Vref and normally you could set between 21 to 43.5V. If the trimmer is indeed changing Ohmic value when you turn, then I would be very suspicious of Q2 and Q3 first when having VGS on Q4. Does Q3 show healthy Vbe?
the 5,37 was on Q1
on Q4 there is Vgs 2,2v
Vbe = 0,62v
still I do not understand
what should be normal readings on tippoints in the sence circuit?
on Q4 there is Vgs 2,2v
Vbe = 0,62v
still I do not understand
what should be normal readings on tippoints in the sence circuit?
2.2V is little. The sense circuit must be tied to the force circuit terminated with a load consuming much less than the CCS circuit provides. It should show Vout at its tips too. Is it configured like that now you measure?
Should only see VGS across it when all is working well. This version has been built successfully many times in this thread, you will surely debug it.
Found it!
I build the shunt as double mono
so I needed to increase R1
I will finish this weekend case
and than listening........
I build the shunt as double mono
so I needed to increase R1
I will finish this weekend case
and than listening........
