AC (+) and (-) finder circuit

[Eplanet]

hello all
can you help me for making a circuit for finding AC (+) ans (-) in main power.
thanks

 

[blueroomelectronics]

Do you mean hot & neutral? Depends on your country what colors are used. In Canada & US Black is Hot & White is Neutral.

 

[Eplanet]

Do you mean hot & neutral? Depends on your country what colors are used. In Canada & US Black is Hot & White is Neutral.

no i mean phase(+) finder between 2 wires

 

[BrownOut]

Any DMM will do:

Measure between each phase and ground.

The phase which reads > 0 will be the hot wire. The phase that reads 0 ( or very nearly so ) is the neutral.

 

[picbits]

If your electrics have a ground on them then just connect three neons with limiting resisors across each combination.

The node that has 2 lit neons on it is the live.

 

[Hero999]

There's is no '+' and '-' with AC, only different phases, phase/antiphase or phase and neutral, depending on what system you're using.

 

[Eplanet]

i know there is no + and - for AC i mean phase and ground. i need electronic circuit for indicating phase and ground for exp with LED or buzzer. this is tool for repairing electrical device.
and i don't want to use DMM. i need very simple device.
thanks

 

[blueroomelectronics]

Neon is the way to go. Simple cheap. You can buy AC mains testers at any good hardware store.

A typical home plug is single phase.

 

[Eplanet]

i have tester but i cant see any light in the sunny day for repairing cooler on the roof.

 

[blueroomelectronics]

Paint the area around the indicators black to increase the contrast. A hollow tube could be used to block sunlight.

 

[Hero999]

Add a photo Darlington transistor and a piezo buzzer.

 

[JimB]

Or use a cheap and cheerfull DMM with an LCD display which can be seen in bright sunlight.

JimB

 

[ParkingLotLust]

Or block the sunlight with your hand/shadow?

 

[BrownOut]

Or block the sunlight with your hand/shadow?

That doesn't even work for the crappy LCD on my Nokia.

 

[Boncuk]

i have tester but i cant see any light in the sunny day for repairing cooler on the roof.

The neon bulb in the tester is fitted with a current limiting resistor since it's operating voltage is approximately 50V. Reduce the value of the resistor until you get a bright orange display. (Additionally you could paint the body (inside around the lamp) of the tester with transparent red colour.)

The light gets brighter if you touch the metal cap on top of the tester and a piece of grounded metal (cooler case)

If that won't help shade the indicator light for better view.

Boncuk

 

[Eplanet]

Add a photo Darlington transistor and a piezo buzzer.

i haven't 220v piezo buzzer.
i think this is better that reduce value of resistor until get more bright.
thanks all

 

[Hero999]

Be careful, if you reduce the value of the resistor too much you'll receive a shock.

Make sure the resistor is rated to 2kV as there can be nasty spikes on the mains.

I would just use a 4.7nF Y2 capacitor rather than a resistor.

i haven't 220v piezo buzzer.

Then use a battery, two watch button cells in series will be enough to make a piezo buzzer beep quietly.