Hello Guys I am a begginer in electronics and need a help in my first circuit. i am making a dark sensor and i used
Transistor BC547
LED
LDR
Resistor 150k ohms
Buzzer
Battery
I Want To Know Whats Problem In This Circuit Which I have Made.
With a 150k resistor to +6V,th most current that could flow through the base of the transistor is 35 microamps; probably not enough. Try a lower value, maybe 20k.
What is the resistance of the LDR at the light level at which you want the transistor to turn on?
And while at it, what is the letter on the tarnsistor after "BC547"? That gives the current gain range.