# Circuits - why doesn't this work

Discussion in 'Primary' started by behindprivateeyes, Nov 29, 2011.

1. ### behindprivateeyes

We built a pretty regular series circuit in school with bulbs and a buzzer. There was plenty of volts in the circuit but the buzzer went off and the bulbs didn't. If we take the buzzer out then the bulbs work, if we put the buzzer in then it works and the bulbs don't. Crazy. Any thoughts?

2. ### behindprivateeyes

We built a pretty regular series circuit in school with bulbs and a buzzer. There was plenty of volts in the circuit but the buzzer went off and the bulbs didn't. If we take the buzzer out then the bulbs work, if we put the buzzer in then it works and the bulbs don't. Crazy. Any thoughts?

3. ### nick909Star commenter

Difficult to say without seeing the sequence.
Can you draw your circuit and post the picture?

Did you try turning them around?

Possibly a problem with the way the current was flowing?

5. ### mystery10Occasional commenter

Try more batteries, in series, and check your bulbs and buzzer were wired in series.

6. ### 24601_

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Which way do you think it should flow????????????????

7. ### Oatibix

The buzzer has a much higher resistance than the bulbs and it will therefore have a higher voltage across it than the bulbs as a result (Voltage = Current x Resistance - current is the same throughout the circuit). This means the bulbs do not have enough voltage to work but the greedy buzzer does!
Try connecting the lot in parallel. In parallel the current will split equally and the voltage will be the same for th buzzer and the bulbs, this should give you enough voltage to run both.

8. ### Oatibix

The buzzer has a much higher resistance than the bulbs and it will therefore have a higher voltage across it than the bulbs as a result (Voltage = Current x Resistance) - current is the same throughout the circuit.
The voltage has to split three ways (bulb + bulb + buzzer) in series, and because the buzzer takes more than its fair share of the voltage, the bulbs do not have enough voltage to work but the greedy buzzer does!
In parallel the current will split and the voltage will be greater for the buzzer and the bulbs, this should give you enough voltage to run both.

9. ### behindprivateeyes

Hi everyone,
Thank you for so many replies. There was easily enough voltage in the circuit but we didn't try everyting parallel. Honestly, these more able children that want to make those things that buzz and light up when the two conductors touch (you know, the skill game).
BPE