I'm trying to have a circuit, which is a simply LED flasher, to be either turned on or off depending on how bright it is. I'm using a photoresistor and a transistor to get this to work.
Here's what I have so far:
**broken link removed**
I unfortunately lost the specs sheet for the photoresistor, and I have little indication now of its resistance value. I have a multimeter, but it's analog and it's highly inaccurate. For example, it reports my 9V battery to be 13V. It's even more inaccurate for measuring resistance. But it looks like the resistance of the photoresistor ranges from 1K ohm in full light to about 40K ohm when I put my finger over it.
Regarding the 5.6K ohm resistor: I picked its value in order to drop the voltage down to about the required voltage to turn the transistor on.
The problem is that my transistor is currently operating as an amplifier. If there's a lot of light, my output has a lot of current; if there's relatively little light, my output has relatively little current. I want it to operate more like an on/off switch. What can I change to do this?
Here's what I have so far:
**broken link removed**
I unfortunately lost the specs sheet for the photoresistor, and I have little indication now of its resistance value. I have a multimeter, but it's analog and it's highly inaccurate. For example, it reports my 9V battery to be 13V. It's even more inaccurate for measuring resistance. But it looks like the resistance of the photoresistor ranges from 1K ohm in full light to about 40K ohm when I put my finger over it.
Regarding the 5.6K ohm resistor: I picked its value in order to drop the voltage down to about the required voltage to turn the transistor on.
The problem is that my transistor is currently operating as an amplifier. If there's a lot of light, my output has a lot of current; if there's relatively little light, my output has relatively little current. I want it to operate more like an on/off switch. What can I change to do this?