LED or Lamp Pulsar Circuit

Astonishing effect 4.5V supply

This circuit operates a LED in pulsing mode, i.e. the LED goes from off state, lights up gradually, then dims gradually, etc. This operation mode is obtained by a triangular wave generator formed by two op-amps contained in a very cheap 8 pin DIL case IC. Q1 ensures current buffering, in order to obtain a better load drive. R4 & C1 are the timing components: using the values shown in the parts list, the total period is about 4 seconds.

Circuit diagram:

LED or Lamp Pulsar Circuit Diagram


R1 = 4.7K
R2 = 4.7K
R3 = 22K
R4 = 2.2M
R5 = 10K
R6 = 47R
C1 = 1µF-63V
Q1 = BC337
D1 = Red Led
IC1 = LM358

Source: Red Free Circuit Design