Howdy folks. My first post here. I just need some confirmation that this circuit will work without releasing any smoke.
My project is a 100W led torch powered by a rechargeable 12V lipo. It think it's quite a common project but none seem to be quite the same.
I'm using a voltage boost controller thingy to change the 12V to 31V for the led, however the fan used to cool the heatsink for the led requires only 12V so that should run directly from the battery?
For switches I have a master kill switch, plus a push button (http://www.ebay.co.uk/itm/SmartSwit...864858&hash=item58edcf92b1:g:k8oAAOSwjDZYkf7t)
Voltage booster: http://www.ebay.co.uk/itm/DROK-LM25...853029?hash=item2a71bd3a25:g:4zEAAOSwmfhX7S7-
I think I've attached a pdf of the an attempted circuit diagram
Anything I need to change up?
Much appreciated
Tommy

 

What you did not include was any information about the LED torch itself. Does it accept a voltage for power or does it need a current to properly drive the LEDs?

 

What you did not include was any information about the LED torch itself. Does it accept a voltage for power or does it need a current to properly drive the LEDs?

My apologise. I don't know much about leds. Here's the link for the led chip I'm using: https://www.amazon.co.uk/CHANZON®-Power-Beads-380nm-840nm-Spectrum/dp/B01DBZHUXA?th=1&psc=1
Can you tell me if I need some type of driver?
Thanks

 

Hello,

The led needs to be current regulated.
A look at the table tells be a current between 2800 and 3500 mA is used:



It looks like this set is made to be used with the 100 W led:
https://www.amazon.co.uk/Tesfish-dr...coding=UTF8&psc=1&refRID=3T96XPNSPSA6DM5PE66Z
But it will be mains powered.

Bertus

 

Hello,

The led needs to be current regulated.
A look at the table tells be a current between 2800 and 3500 mA is used:

View attachment 121022

It looks like this set is made to be used with the 100 W led:
https://www.amazon.co.uk/Tesfish-dr...coding=UTF8&psc=1&refRID=3T96XPNSPSA6DM5PE66Z
But it will be mains powered.

Bertus

The torch does need to run off the 12v battery and be mobile so i can't use that type. But the led and heatsink on that is exactly the same as mine.
Will this be suitable? https://www.ebay.co.uk/itm/252774221840
I thought that the boost converter I had did the same job but with the ability to the voltage

 

Your boost converter is only rated at 3 amps maximum input (36 Watts) A larger step up converter could be used but it should be designed for a constant current output of about 3 amps. It may be possible to modify a constant voltage step up converter to provide a constant current output.

Les.

 

Take a look at one like this where you can set both the voltage and the current.
http://www.ebay.com/itm/1200W-20A-D...109494?hash=item4895d06b76:g:Kl0AAOSw241YmFFq

 

Your boost converter is only rated at 3 amps maximum input (36 Watts) A larger step up converter could be used but it should be designed for a constant current output of about 3 amps. It may be possible to modify a constant voltage step up converter to provide a constant current output.

Les.

They make it look so easy on the YouTube videos. My understanding is that the led should draw 3 amps, so could I use the boost converter I have (https://www.ebay.co.uk/itm/231590063196) in conjunction with this constant current https://www.ebay.co.uk/itm/252774221840 ?
Or would it be best to just scrap the drok boost converter? I kind of need telling what to do. You all have a way better understanding of how the pixies magically travel around so I was hoping to take advantage of this hive mind. Any and all help is appreciated. I liked the idea of the digital display on the drok boost converter but it's definitely not essential.

 

The step up converter in the link that "ronv" has posted looks perfect to drive your LED. (I am suspicious that the specification claims the the maximum output current is 20 amps which is the same as the input current. For a step up converter the output current must always be less than the input current.) A step up converter steps up the voltage bu does NOT step up the power. (In fact the output power will be less than the input power. Probably about 70% to 90%. So for 100 watts into your LED you would need 120 to 130 watts input to the converter which will be 10 or 11 amps.

Les.

 

Your boost converter is only rated at 3 amps maximum input (36 Watts) A larger step up converter could be used but it should be designed for a constant current output of about 3 amps. It may be possible to modify a constant voltage step up converter to provide a constant current output.

Les.

 

Your boost converter is only rated at 3 amps maximum input (36 Watts) A larger step up converter could be used but it should be designed for a constant current output of about 3 amps. It may be possible to modify a constant voltage step up converter to provide a constant current output.

Les.

Oh boy oh boy. I was hoping this thread would be an easy guide to help someone else with the same setup as me but it's getting a bit messy. Perhaps I'm not following what you guys are telling me but in these two builds they use different parts.

In this video (most similar to my build)

(skip to 13:30)
he uses this 600W boost converter http://www.ebay.co.uk/itm/600W-DC-D...243819?hash=item211c088f6b:g:o8oAAOSwA3dYSAHs

And in this video (different input voltage and extra components to me)

(skip to 5:00)
he uses this boost converter http://www.ebay.co.uk/itm/24V-Step-...958219?hash=item2cb435614b:g:xPgAAOSw8gVYB7Yh

Would either of these work for me?

 

The step up converter in your first video is very similar to the one that ronv suggested.

Les.

 

The step up converter in your first video is very similar to the one that ronv suggested.

Les.

Ok thanks ronv and Les for getting me to the right part. It's on order. So does that make the drok voltage booster useless? Or can I still wired it up to make use of the display?
Is the rest the circuit diagram correct?

 

Which circuit diagram are you referring to in post #13 ? The step up converter that you have already bought could be used for some lower power LED lighting project. I have used a similar module (Without the voltage display) for driving 7 1 watt LEDs connected in series from a 12 volts supply. (which requires about 23 volts.). I modified it to give constant current output. The details of the modification are here.

Les.

 

I'd take a look at using 3 12-v lithium batteries in series and just go with that for your voltage source. You would only need 1/3 the A-Hr capacity of those 3 batteries vs the one 12v that you plan to use, for the same run time. You would also need a 3A current regulator, probably easier to put together than the inverter method that you're planning on. Just a suggestion.

 

Which circuit diagram are you referring to in post #13 ? The step up converter that you have already bought could be used for some lower power LED lighting project. I have used a similar module (Without the voltage display) for driving 7 1 watt LEDs connected in series from a 12 volts supply. (which requires about 23 volts.). I modified it to give constant current output. The details of the modification are here.

Les.

I was referring to the file I attached in the original post.
But I think I'll take your advice and save it for a future project. I'm thinking about adding a ring of leds something to this torch, but it will definitely be a later addition. I'll post some photos when it's done

 

I think the first video in post #11 will give you the information to wire the parts together. It explains things in detail so that you can understand what you are doing rather than just building the unit cook book fashion. Your circuit in post #1 is more of your idea than a circuit. you have drawn the stepup converter as a transformer. It is totaly different to a transformer. (For one thing it does not provide isolation the way a transformer does.)

Les.

 

I think the first video in post #11 will give you the information to wire the parts together. It explains things in detail so that you can understand what you are doing rather than just building the unit cook book fashion. Your circuit in post #1 is more of your idea than a circuit. you have drawn the stepup converter as a transformer. It is totaly different to a transformer. (For one thing it does not provide isolation the way a transformer does.)

Les.

Yea I knew that wasn't a step up converter but the program I was using only had a transformer so I just tried to show it by labelling it differently.
Would I still need a current controller if I use these leds https://www.ebay.co.uk/itm/141679345010 with this boost controller https://www.ebay.co.uk/itm/231590063196 ?

 

Yea I knew that wasn't a step up converter but the program I was using only had a transformer so I just tried to show it by labelling it differently.
Would I still need a current controller if I use these leds https://www.ebay.co.uk/itm/141679345010 with this boost controller https://www.ebay.co.uk/itm/231590063196 ?

Yes.
You need a converter capable of constant current.