problem with electronic night light

[dineshmudaliar]

Respected Sir,
I have made a project on electronic night light for my college workshop.I have made the circuit connections but the night is not working.I think I have problem with the circuit connections.I also don't have any information about the 5 pin relay using in this circuit.I am not able to understand to connected which wire with which pin of the relay.So I request you to help me in this project.

 

[ericgibbs]

Respected Sir,
I have made a project on electronic night light for my college workshop.I have made the circuit connections but the night is not working.I think I have problem with the circuit connections.I also don't have any information about the 5 pin relay using in this circuit.I am not able to understand to connected which wire with which pin of the relay.So I request you to help me in this project.

hi,
First connect a diode across the relay coil, else you will blow the transistor.
If you have not already killed it..

Remove the relay from the circuit.
Get a ohm meter and measure across pairs of pins of the relay, one pair should give a resistance reading of low hundreds of ohms, thats the coil.

Using the meter again find which pair of pins give a 0 ohm reading thats a closed switch.
Energise the relay with just the battery connected to the coil, by switching relay ON/OFF you should be able to determine which pair on contacts are closed when the relay is energised, this is the pair for the lamp.

Hope this helps.

If not draw a sketch of the relay base pins and post it here.

 

[Roff]

Respected Sir,
I have made a project on electronic night light for my college workshop.I have made the circuit connections but the night is not working.I think I have problem with the circuit connections.I also don't have any information about the 5 pin relay using in this circuit.I am not able to understand to connected which wire with which pin of the relay.So I request you to help me in this project.

What kind of transistors are you using? If they are PNPs as shown, your battery must be connected with the positive terminal to the emitters of the transistors, and the diode across the relay that Eric added will be backwards.

 

[ericgibbs]

What kind of transistors are you using? If they are PNPs as shown, your battery must be connected with the positive terminal to the emitters of the transistors, and the diode across the relay that Eric added will be backwards.

hi Roff,
Didn't spot that, need new specs.!

 

[aljamri]

and he has 2 negative and three positives in his cell. he has to chose one of the positives.

 

[audioguru]

and he has 2 negative and three positives in his cell. he has to chose one of the positives.

Hee, hee. That is a good one.;D

A non-polarized battery. Is it the same when it is charged as when it is discharged?

 

[Roff]

Hee, hee. That is a good one.;D

A non-polarized battery. Is it the same when it is charged as when it is discharged?

It's a 550 mAH zero volt battery!

 

[audioguru]

A zero volt battery is supposed to be shorted to keep the electrons from leaking out (like a keeper on a magnet).

If the circuit becomes wired correctly then I think the first transistor will be a thermometer and switch the relay when the temperature changes.

 

[aljamri]

you are using a 9v to supply the circuit and 3v to supply the lamp. i don't think taht lamp is enough at night in your workshop.

 

[aljamri]

if your load is 3v lamp, why to use a relay ?! connect your 3v lamp in place of the relay with a proper resistance.