50Hz Square wave from Astable 555

Here’s a quick look at the 50Hz sqaure wave created from a 555 timer to overcome the vehicle anti-theft system.50Hz square wave generator for VATs/Passkey


My weekend project: create a circuit that would create a 50Hz square wave signal to feed into the ECM/PCM on a 1990’s caprice to circumvent the vehicle anti-theft system. Solution? A couple of capacitors, resistors, and a 555 timer. Result: the car runs like a dream. More to come.

Here you go, a site for reading resistor codes:
http://www.samengstrom.com/nxl/3660/4_band_resistor_color_code_page.en.htmlR1 = 10,000 Ohms
R2 = 100,000 + 33,000 = 133,000 OhmsCapacitors: Both are 0.1 microfarad

You are wiring the 555 timer to be astable. Here’s a good tutorial on that:

With those values plugged into this calculator, this gives a 52.283 Hz wave with a 51.812% duty cycle. Hope it helps!

Leave a Reply

Your email address will not be published. Required fields are marked *