LTspice is a free version of spice from Linear Technology, and it is delightfully easy to use, intuative, and seems to work rather well. Note, there is a flasher version 3 Current through component ...

This is a small size led flasher built with the 555 timer IC that is powered from 2 x 1.5V batteries. The circuit can be used as a flashing metronome, dark room timer, memo-reminder or other similar ...

This is a simple flashing led circuit with 2 leds and 2 NPN transistors. It illustrates the behavior of transistors and capacitors and if you use an oscilloscope it will be very easy to determine what ...