Circuitbenders Forum

Please login or register.

Login with username, password and session length
Advanced search  

News:

Author Topic: 555 oscillator + transistor to turn bends on and off  (Read 5787 times)

wax+wire

  • Dayglo Volunteer of International Masturbation
  • ***
  • Karma: 0
  • Offline Offline
  • Posts: 113
555 oscillator + transistor to turn bends on and off
« on: February 10, 2015, 07:14:47 AM »

I stumbled upon this excellent idea : http://www.nerdybynature.com/2009/10/06/glitch-lfo/#comments

It takes a basic 555 lfo circuit and hooks up a transistor to open and close the bend (or anything from what I gather)

Only issue, hooking it up doesn't seem to work for me.

What possible transistors would work in here?

Or should i stick a load resistor before the switch?  (i am running it off 7.5v - 9v from a casio sk
Logged

wax+wire

  • Dayglo Volunteer of International Masturbation
  • ***
  • Karma: 0
  • Offline Offline
  • Posts: 113
Re: 555 oscillator + transistor to turn bends on and off
« Reply #1 on: February 11, 2015, 12:09:29 PM »

a 2N2222a transistor worked sweet.

i put a 1k resistor in line with the base of the transistor, but i don't think it does anything. 
Logged

Circuitbenders

  • crustypaul
  • Admin
  • This person is dangerously insane.
  • *****
  • Karma: 1102
  • Offline Offline
  • Posts: 2451
    • Circuitbenders.co.uk
Re: 555 oscillator + transistor to turn bends on and off
« Reply #2 on: February 11, 2015, 03:24:41 PM »

A 1k resistor in line with the base will limit the current used to turn on the transistor. This is necessary if you're using something like a microcontroller output to drive the transistor, as theres a limit to how much current the IC can supply. Probably an idea to read up a bit on how transistors work. Theres load of stuff on the net.

You might get better results using the 555 to drive a 4066 switch, or even a reed relay being switched by the transistor. How well a basic transistor switch works will depend a lot on what its switching.
Logged
i am not paid to listen to this drivel, you are a terminal fool

wax+wire

  • Dayglo Volunteer of International Masturbation
  • ***
  • Karma: 0
  • Offline Offline
  • Posts: 113
Re: 555 oscillator + transistor to turn bends on and off
« Reply #3 on: February 12, 2015, 08:29:12 PM »

Thanks.

I think i do need to read up on them.  when i hit a problem i started reading about it, but it did my head in a bit to be honest.  might need to start at the dummies version.
Logged