The circuit to light LED with single 1.5V battery is usually based on a
blocking oscillator or a charge-pumped voltage doubler.
This is another (but similar to charge pump) way to flash LED with 1.5V
battery. The base-R voltage becomes nearly double the Vcc while making oscillation
timing of astable multivibrator. LED can be flashed if it is attached aside.
Since the LED discharges the C electricity, oscillator timing is shortened.
Figure 1: 1.5V LED flasher
Normal astable multivibrator ( without LED )
LED attatched timing
LED discharged electricity
Figure 2: LTspice simulation
You can see the light at the marked points.
Figure 3: Implementation
Osamu Tamura @ Recursion Co.,
Ltd.
13 Jan. 2007