Pre-Order - Dummy Loads

[hybridz0rz]

Iv been looking around on different forums, and there arent to many dummy loads for sale that can be used for Red, green and Blue laser drivers so im going to build some Dummyloads.
The Pre-Order price is 15USD + Shipping costs.

Specs:
7 Diodes rated for 1A / 400V
1 Watt 1 Ohm resistor
screw terminals (for easy use)
And a Black Custom PCB.

Parts will be arriving soon!
So if you order now (27.01.2013) (DD.MM.YYYY) there will be a 2-3 Week delay before the boards will be assembled and Shipped!
Send Pm's if you are interested in one

I build them in groups of 30 at a time, So i will updated this thread when i'm sold out and when a new batch of 30 is ready to be sold.
(Pictures will come as parts roll in)

-Hybridz0rz

[lasersbee]

Anyone requiring a Dummy Test load can build one themselves
with a few 1N4007 Rectifier diodes and a 1 Home 1-2 watt resistor
built on a Perf Board or even just point to point for about $1.00.



There are members on LPF that are selling Multi-Amp Test Loads
for Lasers that require higher currents than 1 Amp.


Jerry

[jaycey]

Whats the diodes for? I only use a 1 ohm resistor. Well that was when I was making my own drivers.

[tribble]

The diodes provide the voltage drop the real LD would present to the driver. Standard silicon diode has about a 0.7V voltage drop across it regardless of (normal LD) currents. Stack 'em up in series to simulate the drop across popular diode types.

[tribble]

Of course, it goes without saying that the voltage drop across the resistor is directly and linearly proportional to the current, via ohm's law. So if you know the resistance exactly, you can measure the current through the loop by reading the voltage across the resistor. If the resistor is 1 ohm, it makes the math easier for direct reading of current on the 'volts' scale of the multimeter without any math.

Of course, it the resistor is not exactly 1 ohm, or if its resistance changes with temperature, your current reading will be affected. So, you want a precision, high-power resistor for this job, unless you like ballpark figures for your laser diode currents. :-p