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ArcticMyst Security by Avery

Bleeder resistor on DDL

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Feb 1, 2008
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I'm looking to make my 445 labby work more like an Argon.. with a separate head, power supply and controller. If I'm going to be using (for example) a 5 pin connector cable between the "head" and the power supply, I'll want to make sure that the driver circuit in the power supply doesn't let its capacitor discharge across my diodes when I need to break, and remake that connection. (Oops, did I say diodeS?)

I figure a bleeder resistor across the driver's anti-transient capacitor would do the trick. The driver may have up to 1.25A to dissipate, so I suspect that if the cap is charged to 4.4V, I would need a ~5W resistor. BUT how much resistance do I need?

I don't want the resistor to be pulling extra AMPS of current while the thing is running, but I also don't want to accidentally break, and then remake that connection so fast that the cap doesn't discharge across the resistor in time.

Would I not even need a resistor if instead I installed the cap across the diode/s, separate from the driver? This would mean that the 5 pin connector would break the connection between the cap/diodes and the rest of the driver...

I hope this makes sense. I'm not very good with electronics, so I appreciate any help.

Also, if I'm going to have the head as a separate unit, is there any need to protect the diodes from any further esd that might occur? I feel like it would just be the same as if I were using the diodes bare, without anything stopping esd from going down the pins.
 





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The only way I would do this is; the umbilical cord must be soldered on both ends. (non-removable)
Pin connectors are to way too subject to momentary opens and continuity changes. Laser diodes are too sensitive to have anything except a well soldered connection.
Also, the wires used in the umbilical would have to be top quality in order not to develop opens from the bending and flexing.
Also, if I'm going to have the head as a separate unit, is there any need to protect the diodes from any further esd that might occur? I feel like it would just be the same as if I were using the diodes bare, without anything stopping esd from going down the pins.
YES, if you were to do this, the diode would need to be shunted when off the umbilical.
Neat idea though, I have never seen it done on a hobby laser.
 
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