ne556 ne555 triangle wave?

synthesist · Posted: Sat Jan 21, 2012 4:14 am Post subject: ne556 ne555 triangle wave?

hey,

I am considering about building a (preferable) low component FX-Gear for processing a drummachine or some cheesy toy keyboards.
It should containe a VCA and other stuff that I wanna gate on and off.

So is there a way to get a triangle-like wave from a 555 timer? One that can be pitched without losing shape?

I know there is a trick to get some triangle waves from cmos, but is a 555 meant to do a triangular too?

PS. the wave needs to get very low for LFO but also up to audio.

thanx

Mongo1 · Joined: Aug 11, 2011 Posts: 411 Location: Raleigh NC

One thing you might look at is buffering the voltage that appears on the main timing cap of the 555. It's not a perfect triangle, but it might serve your purposes. Just use a LM324 or similar opamp to buffer it.

Gary

synthesist · Posted: Mon Jan 23, 2012 1:33 am Post subject:

...so the output of the wave would be pretty weak by itself.

Would have just been too cool to be true. I mean to to get usefull non-square waves by using the ne555 by its own. Anyways this project will be one for the future since I wanna finish my modular gear first.

Thanx,
Xonrad

Mongo1 · Joined: Aug 11, 2011 Posts: 411 Location: Raleigh NC

mrkva · Posted: Wed Jan 25, 2012 7:58 pm Post subject:

Its not a perfect triangle, but I did this:

http://falstad.com/circuit/#%24+1+5.0E-6+5.023272298708815+64+7.0+50%0Aw+192+160+160+160+0%0Aw+160+224+192+224+0%0Aw+160+224+160+256+0%0Aw+160+256+192+256+0%0Ac+160+256+160+320+0+1.0000000000000001E-7+5.4694501216872835%0Ag+160+320+160+336+0%0Aw+96+96+256+96+0%0AR+96+96+48+96+0+0+40.0+10.0+0.0+0.0+0.5%0AO+384+192+448+192+0%0A165+192+128+208+128+2+0.0%0Aw+256+96+320+96+0%0Aw+320+96+320+160+0%0Ac+384+192+384+240+0+1.0E-8+1.0108301834052384%0Ag+384+240+384+256+0%0A174+320+192+384+192+0+100000.0+0.19310000000000002+Glide%0Aw+352+176+384+176+0%0A174+96+128+160+128+0+100000.0+0.9851000000000001+Freq%0Aw+160+128+160+160+0%0Aw+96+96+96+128+0%0Ar+160+160+160+224+0+22000.0%0Aw+384+176+384+192+0%0Aw+96+96+128+112+0%0Ax+82+164+129+170+0+24+freq%0Ax+350+155+407+161+0+24+glide%0Ao+4+32+0+35+10.0+3.90625E-4+0+-1%0Ao+8+32+0+42+20.0+9.765625E-5+1+-1%0A

synthesist · Posted: Sun Feb 26, 2012 9:14 am Post subject:

thanks mrkva for the animation. It doesnt have to be a real triangle. I search for something thats just not a suarewave.

But if use only one Transistor as a buffer for Tri output of the capacitor it could be fine, or? I mean one Tranisistor should do the job.