Remote Timer Project
Standing outside all night watching the heavens is great in the Summer, but when the bulb drops below zero it is not so much fun. I was considering building a remote device when I stumbled across this website. At the bottom of the page it said "if you need a timer circuit for a particular application, email with details of your exact requirements".

Incredibly, 5 days later the small circuit you see in the picture below dropped through my letter box. It took about an hour to dismantle my Canon RC-1 remote and hook it up to Neil's electronics.

What the electronics does, by dint of a PICAXE programmable microprocessor, is operate a relay (the blue thing) which simulates a human pressing the button of the remote. It can be programmed by a simple push button to give exposure lengths from 5 seconds to 10 minutes. Once started it will give repeated exposures while the human operator keeps warm indoors.

The timing sequence allows for a small delay while the camera does a mirror lockup (to lessen vibration), and if I choose to let the camera do dark frame subtractions the timer will take that into account.

All that is now needed are some adhesive Velcro tabs to attach the remote to some convenient spot on the telescope.

  Testing the remote timer

    The modified Canon remote and an ordinary one.  
The timer.

The red LED confirms the time set, eg 10 seconds it flashes twice;
60 seconds it flashes 12 times.

The green LED shows when the relay closes.

The mode switch is for when I want camera dark frame subtraction.
The remote attached with Velcro.

The infra red signal is aimed at the hand grip where the sensor is.

    After prolonged use the timer started to give intermittent faults so a new device was built from scratch using a Picaxe 18X chip.

An LCD display is used to provide a more user friendly interface.

Set times from 30s to 10 minutes can be chosen.
The display counts up in seconds and also shows how many frames have been taken.

The right hand button allows frames to be taken manually.