Lamp Burnout Detection

[7rots51]

burnout detection lamp

Hi
I need a sch for detection of the burned lamps that work with 220VAC voltage and give a logic 0 or 1 for Lamp-OK and Lamp-NOK.

 

[flatulent]

You could put a small resistor in the ground side of the lamp and then measure it with a comparator. The output will toggle if the lamp is conducting and not when it is open. Have a retriggerable monostable on the output that has a pulse width of time equal to several periods of the line frequency. Once the lamp opens the comparator will no longer trigger the monostable.

A cheaper version would have a diode to rectify the voltage across the sense resistor which is the sent to a logic gate.

 

[klug]

Hmmm, some idea. To avoid connect with 220V AC you can check lamp without electrical connection. Place bipolar transistor in (or near) lamp socket. Use it as temperature sensor. If lamp is not working it will be cold or hot when lamp is ok.

 

[toonafishy]

Simple and foolproof - used on all ship navigational lighting. Put a relay coil in series with the lamp lead. The relay coil pull in CURRENT should be about the same current as the lamp. If the lamp is on and drawing current, the coil pulls the relay contacts and they close. If the lamp burns out, the relay drops out and the contacts open. Of course, you will have to add some circuit to your relay contacts to indicate GO - NO GO.

 

[Sonic]

A non intrusive idea is to use a cheap fiberoptics cable. Place one end in proximity of lamp to pick up the light (away from the heat), and use a photodetector to monitor it on the other end!

 

[Ante]

Try using a small toroid core. Make 10 turns with the live wire as a primary and 10 to 100 turns (depending on the load) as a secondary. Rectify and parallel with a Zener 4.7V and you have a logic hi for “lamp OK” and logic LO for “lamp defective”.

Ante :roll:

 

[Ante]

This is how I was thinking!

Ante :roll:

 

[Ante]

This is how I was thinking!

Ante :roll:

 

[7rots51]

WHAT ABOUT SOLUTIONS WITH OPTOCOUPLERS ?!

 

[Ante]

7rots51,

An opto will galvanic separate the circuits but so does the toroid.

Ante :roll:

 

[mayaka2004]

BY FAR THE BEST SOLUTION IS TO MONITOR THE OVERALL CURRENT FOR A FULL LOAD

THIS IS A STEP ONE

AND USE ONE SENSING CIRCUIT TO TELL YOU WHAT LAMP BURNED OUT
BY THE CURRENT THE REST USE WITHOUT YOUR BURNED OUT LAMP
BY SIMPLY PERFORMING A LOAD SENSE USING A CURRENT SENSE IN THE FORM OF AN A/D CONVERTER

IT IS SIMPLE TO FIT WITHOUT HAVING TO MODIFY ANY EXISTING CIRCUIT

STEP 2

EACH LAMP SAY AT 240V @ 60 WATT LAMP WILL HAVE A RESISTANCE OF 50R



SO IT IS EASY TO "SCAN" THE WHOLE CIRCUIT
USING DIFERENTIAL RESISTANCE

WHAT YOU WOULD HAVE TO DO IS WRITE SOME SOFTWARE FOR A PIC
THAT CAN SCAN YOUR CIRCUIT FOR BLOWN BULBS
USING AN A/D AND A FEW COMPONENT
AN AN LCD TO SHOW THE POSITION

COST ABOUT 15$

I ATTACHED A METHOD {QUICKLY DRAWN }

SO THIS WILL RUN

THE RELAYS ARE NORMALY CLOSED SIDE TO THE MAINS

THE ACTUAL SENSE AND ANALYSE IS DONE WITH NO SUPPLY

YOU ALSO NEED BREAK BEFORE MAKE CONTACTS

 

[gil]

Interesting topic. Please remember that lamps could have VERY large current when burn out. It can be something like 20 or more times the normal current of the lamp and last at least half hemicycle. It is produced by the ionization of the gas inside the lamp when the lamp filament is cut by any reason. The current then, is limited only by the power line impedance. Any circuit attached in series with the lamp should stand this type of surge of energy.

 

[7rots51]

In fact I want to use it for 4-way (street) GREEN-YELLOW-RED lights.
I want to detect the burned lamps and report it automatically,(through a control system).

I use a Triac to ON/OFF the lamps ,I think by adding a simple R(100k) + OPTOCOUPLER (H11L1) across the TRIAC I can sense the burned lamp during ON state of the lamp.

One module control the lamps on/off and the same detect the burned lamps.

Do you have any new offer with these new info.