Hi everyone
I have build a voltage divider from to resistors R1 and R2 (as shown below). I calculated R1 and R2 to let me have Vout=3V. Then I attached a load and soon realized that Vout changes under load.
Then I thought of modelling the whole thing as a voltage devider with R2 and the RL1 in parallel. After reading a bit this turns out to be the thing to do. But what value to use for RL1 (and maybe RL2, please see discussion below) ?
I've tried to abstract my circuit as much as possible, if it's too abstract and I've thrown away features, please let me know and I'll draw it in full detail.
Basically RL1 is PCB from a wireless doorbell receiver and the wires 1 and 2 are there to supply this pcb with 3V as was normally supplied to the doorbell receiver by 2x 1.5V batteries.
Wire 3 and 4 are two wires (ground and positive) which originally led to a LED in the doorbell (supplies ~3V to the diode). Now the ground is connected to ground instead of a pin on the LED and positive is connected to the base on a NPN-transistor in a 555 timer circuit.
Wires 5 and 6 supplies the 555 circuits (one monostable and one astable) with 9V and is hence connected to Vcc = 9V and ground.
I simply do not know where to measure the resistive value of RL1 (and/or RL2) so I can perform my voltage devider calculation.
Should I connect my ohm-meter to
Thank you very much in advance
Wuhtzu
I have build a voltage divider from to resistors R1 and R2 (as shown below). I calculated R1 and R2 to let me have Vout=3V. Then I attached a load and soon realized that Vout changes under load.
Then I thought of modelling the whole thing as a voltage devider with R2 and the RL1 in parallel. After reading a bit this turns out to be the thing to do. But what value to use for RL1 (and maybe RL2, please see discussion below) ?
I've tried to abstract my circuit as much as possible, if it's too abstract and I've thrown away features, please let me know and I'll draw it in full detail.
Basically RL1 is PCB from a wireless doorbell receiver and the wires 1 and 2 are there to supply this pcb with 3V as was normally supplied to the doorbell receiver by 2x 1.5V batteries.
Wire 3 and 4 are two wires (ground and positive) which originally led to a LED in the doorbell (supplies ~3V to the diode). Now the ground is connected to ground instead of a pin on the LED and positive is connected to the base on a NPN-transistor in a 555 timer circuit.
Wires 5 and 6 supplies the 555 circuits (one monostable and one astable) with 9V and is hence connected to Vcc = 9V and ground.
I simply do not know where to measure the resistive value of RL1 (and/or RL2) so I can perform my voltage devider calculation.
Should I connect my ohm-meter to
- Wire 1 and ground, and let everything be connected.
- Wire 1 (disconnected from the voltage divider) and ground, and let everything else be connected
- Wire 1 and wire 2 with wire 4 connected to RL2 (555 timer circuit)
- etc
Thank you very much in advance
Wuhtzu
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