Hi,
I have on Dec 3. 2019 had Ingelwoodpete's commentary concerning a hardware switch using a NPN transistor and a PNP transistor (https://picaxeforum.co.uk/threads/timeout-again.31701/page-2#post-329521 shows the diagram), which has worked OK. I am now taking a closer look at the switch. I have looked at 2 situations:
1. when there is no load to be controled attached to the PNP transistor
2. when thare is a load to be controled attached to the PNP transistor. The load is a HC-12 Transceiver and a controller turning a motor either way
and I get:
My problem is that "P output of PNP" not is 0 (but 0.7) when there is a load. I thought that "p output of PNP" only was dependent on the 3 inputs to PNP.
I am getting power from a wall-wart.
The use of R3 (10 k Ohm) makes no difference.
I am using the switch to save battery power.
Can anyone explain?
best regards
torben
I have on Dec 3. 2019 had Ingelwoodpete's commentary concerning a hardware switch using a NPN transistor and a PNP transistor (https://picaxeforum.co.uk/threads/timeout-again.31701/page-2#post-329521 shows the diagram), which has worked OK. I am now taking a closer look at the switch. I have looked at 2 situations:
1. when there is no load to be controled attached to the PNP transistor
2. when thare is a load to be controled attached to the PNP transistor. The load is a HC-12 Transceiver and a controller turning a motor either way
and I get:
Code:
No load:
Base of NPN Base of PNP P output of PNP
0 4.5 0
0.730 3.87 4.64
Load:
Base of NPN Base of PNP P output of PNP
0 4.45 0.7
0.730 3.862 4.63
I am getting power from a wall-wart.
The use of R3 (10 k Ohm) makes no difference.
I am using the switch to save battery power.
Can anyone explain?
best regards
torben