My site was hijacked last year and I had to make some tough choices. In the end I cleared out the old site and my astronomy articles went with it.
But I still have the images so here they are again quickly put together in a short article.
(Note: The images are all I have of the original article so the text is written from memory and references to Martin Burri's circuit. Please check your wiring and don't just rely on this description. If you spot any errors please let me know.)
The circuit I chose to implement was Martin Burri's amp-off circuit as it looked simple to do and I had the components...
Bending the stiff legs of components with pliers means you can solder between the pins on the CCD board and the components will hold themselves rigid enough to prevent short circuits. I think this is called the rats nest style!
I started by soldering down the emitter of transistor Q2 (refer to Martin's circuit) to pcb pad 8 of the CCD on the bottom side of the pcb. The Q2 collector lead was passed through to the topside of the board using a via-hole ready to solder to pin 8 of the CCD itself. (you might want to pass a fine insulated wire through the via-hole instead if you are concerned about short circuits).
The picture below shows the zener D1 soldered between the emitter and collector of Q2. Capacitor C1 (yellow component) is soldered between pad 9 of the CCD and the Q2 collector. The Q2 emitter is soldered to the pad 8 of the CCD.
This image shows transistor Q1 now in place. R1 (10k resistor) provides 5v from a pin on the black inter board connector. R2 was soldered to the base of Q1 and the amp-off control wire was soldered to R2 directly. R3 joins the collector of Q1 to the base of Q2.
Pin 8 of the CCD is carefully cut close to the board. The pin is then bent up and the emitter wire of Q2 is solder to pin 8.
The two boards can then be put back together to complete the amp-off sandwich.
Sandwich is now ready to be tested....
only a small amount of amp glow remains
Here is a picture of the completed camera: