It is with deep sadness that I wish to report the passing of my first Sony diode. :'(
It was in an instant - and then it was gone. Here's what happened so that you, dear reader, shall not need to suffer the slings and arrows of suffering and remorse as have I this foggy eve.
I had mounted the diode in a three pin transistor socket, and had previously noted that the leads weren't quite long enough to fully engage the socket, but it was pretty secure, so I let it be.
As I was focusing the beam this evening in the fog (pretty!!!!!), the diode slipped for only a fraction of a second out of the socket - probably only one pin. The pressure of my focusing it live caused it to slip out - and then immediately back in. It died instantly.
What happened? It seems that the driver circuit - probably true with them all - goes to full Vcc (in my case, 6vdc) when there is no load. The capacitor, attached as a spike preventor, then charges to full Vcc. The diode, on reinsertion, then gets a full 6v discharge from the cap - plus the driver circuit. I would guess that in the ~ 30ms that the diode disconnected for, the cap charged to 6v, and subsequently dumped 6v at well over an amp to the diode for a ms or so, effectively turning my beautiful sony laser diode into a dim at best regular LED.
The moral of the story is this: Even when prototyping, SOLDER your diode into the circuit to prevent disconnection/reconnection. I socket things because I like to keep leads pristine until installation in a finished product. Not worth it. SOlder, leave the leads at maximum length.
NEVER reconnect a diode into the driver circuit until you have shorted the cap and outputs of the driver circuit.
Buy spares! I did... and now I will go REMOVE that damn socket and SOLDER in a new diode!
I just hope the next one burns as well as the one I just cooked. That thing ROCKED! I was burning holes in everything!
:exclamation Learn from my mistakes!!!!
Dave
It was in an instant - and then it was gone. Here's what happened so that you, dear reader, shall not need to suffer the slings and arrows of suffering and remorse as have I this foggy eve.
I had mounted the diode in a three pin transistor socket, and had previously noted that the leads weren't quite long enough to fully engage the socket, but it was pretty secure, so I let it be.
As I was focusing the beam this evening in the fog (pretty!!!!!), the diode slipped for only a fraction of a second out of the socket - probably only one pin. The pressure of my focusing it live caused it to slip out - and then immediately back in. It died instantly.
What happened? It seems that the driver circuit - probably true with them all - goes to full Vcc (in my case, 6vdc) when there is no load. The capacitor, attached as a spike preventor, then charges to full Vcc. The diode, on reinsertion, then gets a full 6v discharge from the cap - plus the driver circuit. I would guess that in the ~ 30ms that the diode disconnected for, the cap charged to 6v, and subsequently dumped 6v at well over an amp to the diode for a ms or so, effectively turning my beautiful sony laser diode into a dim at best regular LED.
The moral of the story is this: Even when prototyping, SOLDER your diode into the circuit to prevent disconnection/reconnection. I socket things because I like to keep leads pristine until installation in a finished product. Not worth it. SOlder, leave the leads at maximum length.
NEVER reconnect a diode into the driver circuit until you have shorted the cap and outputs of the driver circuit.
Buy spares! I did... and now I will go REMOVE that damn socket and SOLDER in a new diode!
I just hope the next one burns as well as the one I just cooked. That thing ROCKED! I was burning holes in everything!
:exclamation Learn from my mistakes!!!!
Dave