LED Emergency Lighting Supply Circuit?

Gerald Bramwell's picture

Offline

Joined: Jan 12, 2020

Replies: 2
LED Emergency Lighting Supply Circuit?
January 12, 2020 - 5:49am

Hi,
I have a couple of portable LED lighting units where the control boards have failed. They use a 6 volt Sealed Lead Acid batteries. When the mains supply is on the LED lights are off and the battery is trickle charged and when the supply fails the LRED lights come on.
The actual supply to the control PCB is 12 volt. I have searched for a suitable suply design but not been able to find one. Can anyone help with the design of a suitable circuit or point me in the right direction? I am capable of building a circuit but not designing one.
Any help much appreciated.

Gerald

Debasis Parida's picture

Offline

Joined: Aug 22, 2019

Replies: 72
Mention your LED specifications
January 12, 2020 - 9:54am

Please mention the forward current and voltage specifications of the LEDs, so that it will be easier to reccomend you the exact solution.

Gerald Bramwell's picture

Offline

Joined: Jan 12, 2020

Replies: 2
LED specifications
January 12, 2020 - 10:19pm

Thanks for the reply,

I do no know the LED spec and the control boards have failed. There are two banks of LEDs 18 LEDs all in parallel in three banks of 6 drawing 20ma at 6v and a circular bank of 7 LEDs in parallel drawing 8ma at 6v. These banks can be one or the other or both off via a dptw switch. Sorry I cannot be more specific but I think the switch does not control the LEDs directly. Thinking of a circuit to tricle charge the battery, detect power failure and swithh on one of the banks of LEDs depending on the position of the switch.

hope that helps.

Gerald

Sourav Gupta's picture

Offline

Joined: Feb 12, 2018

Replies: 102
Discard the battery
January 14, 2020 - 2:02am

For this cas, how you are getting sure that the driver is failed?

Discard the battery, use a similar voltage (6V) of the battery using a power adapter, turn on the LEDs, kindly check whether it is working or not?

Do you have multimeter, check the continuity of the switch as well.

It is very rare that LEDs driver circuit fails. Not sure about the charging circuit.

Kindly share confirmed information about the switch continuity, LEDs are ok or not and then whether connecting an external power supply same as the battery voltage working or not.

Gerald Bramwell's picture

Offline

Joined: Jan 12, 2020

Replies: 2
LED Emergency Lighting Supply Circuit
January 14, 2020 - 4:27am

Switch working okay, LEDs working okay, works with external 6v supply for a few seconds when battery disconnected. A few components over heat in what I think is the power detect and charge circuit and a 1watt resistor on all boards has burnt out. The units are LLoytron D1002GR LED Emergency Rechargeable Lantern. I have tried to get hld of a circuit diagram but to no avail.

Sourav Gupta's picture

Offline

Joined: Feb 12, 2018

Replies: 102
Image of the circuit
January 15, 2020 - 12:12am

Can you post a image of the circuit?