Transistor Triangle Wave Osc V2

167

02:46:06

Triangle and square wave generator circuit using transistors (redesign). 

published 7 years ago

Sheen140

7 years ago

Also take the description with a grain of salt, that is just my attempt to justify this monstrosity of a circuit...

hurz

7 years ago

needs a lot of rework ...

Sheen140

7 years ago

Yeah its definitely not the most elegant circuit

JoelCB

7 years ago

I have one that works! Look at my circuits.

Sheen140

7 years ago

Oh yeah yours seems pretty stable @JoelCB! Could be useful in future projects for me

hurz

7 years ago

you can replace the current source with a resistor around 2.5kOhm However, then you need a little higher supply to 6V. Check this with a current source and 5V http://everycircuit.com/circuit/5504890949074944

Sheen140

7 years ago

@Hurz yeah I had been wondering whether to just replace that pnp transistor current source with a resistor to simplify the circuit myself. Originally I had picked a current source because I wanted the capacitor voltage to ramp up and ramp down linearly as opposed to the logarithmic charge/discharge curve that would come from using a resistor, but for the small peak to peak voltages that the capacitor charges and discharges to I'm not sure having the current source really makes a difference. Thanks for the suggestions by the way! You seem to have knack for finding ways to optimize circuits

hurz

7 years ago

if you have a high enough supply voltage the resistor might be linear enough. depends on your requirements. In theorie if you have an infinite high voltage and resistor you get a perfect current source. Play with 24V and 24kOhm for 1mA you will not see any differences to a current source. But stay far away from 24V, mean work below 5V and keep 19V as headroom. Have fun with electronics

hurz

7 years ago

something like this http://everycircuit.com/circuit/6048259106406400

hurz

7 years ago

BTW, the cap to ground is just a trick to fake everycircuit, it avoids CFS 'cant find solution'

Sheen140

7 years ago

Oh God thank you for telling me that capacitor trick, I don't know how many times I've run into that error

hurz

7 years ago

its not a 100% trick, but for 90% of all circuits it helps to overcome CFS startup issue

hurz

7 years ago

a more simple one is just a switch at power supply, or at any clever position in circuit.

hurz

7 years ago

there are more workarounds, however, if you continue with evercircuit you will see them all sooner or later

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