Re: Cheap 1.2 amp driver running off 2x 3.0v lifepo4 cells that iam using. Only $1.99
I'm actually using this same driver for my builds. For the price there isn't a better alternative. My units came set at 1.25Amps (0.2Ohm resistor). I'm using 2 Li-ion 18650 cells and they last very long time...
Thanks for your post!
I think that's exactly what I'm going to do. That threading will cause some problems though. Its step looks small (M11x0,5 ?) and taps like that are hard to find. Maybe I'll have to order one for machining...
BTW, nice beamshot in the first picture :)
Has anyone tested these modules with the Casio 445nm diodes? I need to know if they provide good enough thermal contact with the diode case. I know they are not press-fit like most 12mm modules, but rather have a small retaining ring holding the diode in place. Not sure whether or not this is...
@lasersbee
I made comparison plots of the data you posted about your A130 and A140 diodes.
P/I/V plot:
Efficiency plot:
The A140 diode not only needs less current to produce the same power, but also has lower voltage drop.
Both diodes have highest efficiency around 1000mA...
Thanks!
I strongly advice you to use a test load (2x 1N4001-1N4007 diodes) in case something goes wrong.
An oscilloscope, if you have one, would be very useful for monitoring the output waveform.
This is the conceptual schematic:
Red graph is the input signal, orange - output.
D882 (or 2SD882) wasn't in the component database so I substituted it for BCP68.
BC847A could be substituted for any general purpose NPN transistor.
There probably should be added some capacitors. There were 2...
I took the schematic of the driver from a 100mW DX module some months ago:
P.S.: I was working on a PWM enabled version of this schematic but the drawings are buried somewhere. I'll try to find them.
Isn't the Microboost a boost driver? If so, the current you are measuring at the tailcap and the current flowing through the diode will be completely different values.
(somebody correct me if I'm wrong)
A short-circuited battery CAN supply that amount of current for a short time. And the battery in the first post is short-circuited. Furthermore, my cell phone jammer draws well over 3Amps and is powered from AAs. Once I accidentally short circuited these batteries and the wires started...