A red LED torch is essential for preserving your dark adapted vision at night allowing you to read star charts as well as setup and take down your accessories safely. The red wavelength is specific to retaining your night sight so you can observe without distracting white light that destroys dark adaption for long periods.
If you need an economical and compact astro torch for your private use, then this is the circuit you are looking for. This lightweight affordable astro torch is great for field use in darker locations. Battery powered and with LED technology they will last far longer than ordinary torches.
The led torch circuit is nothing but an astable multi vibrator (AMV) wired around the ubiquitous timer chip LM555C (IC1). Components R1,R2 and C2 sets the oscillator frequency. This circuit has been designed to provide a high-frequency pulsed clearly visible red light, formed by one 5mm clear red LED (1). An optional LED (2) switching facility is included to increase the light output. The led torch circuit can be incorporated in to a small palstic box. With a 9V PP3 battery (plus the astable configuration) you can expect a long battery life.