Common test loads and 445 diodes

[tazlynx51]

Is the resistor in this circuit used just as a shunt resistor or is it necessary as part of the load? The reason I am asking is that the metering system I am building as part of my "lab" supply will already have the 0.1 ohm resistor in its circuit. :thinking:

George

 

[Bionic-Badger]

The resistor is there to measure the current over (as voltage), and that's it. Don't include it in any build involving the laser itself as it will just sap power.

 

[tazlynx51]

Great, that's what I thought, but I wasn't sure...Now to make up my mind which driver to get...Hmmmm.

Sorry, didn't mean to hijack this thread...

George

 

[Autist]

Hi All,

What exactly is the issue with 445nm diodes and common test loads using the 1N4001, (I think that's the number), diodes?

I know we're trying to put a lot of current through them but I'm curious that, when using a microboost,

it's suggested to just use the Red setting instead of the Bluray one. Do I get the same current being supplied to my 445 diode if I set my driver to, say 800mA using the Red setting?

If this is the case, can I just use the Red setting when using an 8x Bluray? If not why not and how far out will the actual current output be?

I don't fully understand buck/boost, or just boost, circuits so don't understand how they up convert, (except that it's to do with back EMF spikes from inductors etc), and what correlation output voltage has to output current, for a fixed input voltage and input current. Is it a simple power in = power out conversion?

Any enlightment welcome.

Thanks,

M

Hi Morgan,

I have just set my microboost for the 445 nm diode I received from Scopeguy20 (Glenn :thanks and I used the Rkcstr test load.
On the RED setting, the DMM reading was 854 mV, whilst using the the same battery and driver without altering the pot, the BLUE setting on the test load the DMM read 841 mV.

Hope this helps.

Best wishes

David

 

[LazyBeam]

Also the ability to use with a tactile switch (though I'll be using a clicky or high-current momentary push button) would be neat for those making pointer-style builds.

Just buy a 1A rated tactile switch.

 

[BShanahan14rulz]

Yeah, true. I guess it's silly of me to have thought that just because all the cheap pointers come with crappy switches doesn't mean that they aren't available.