7 Transistors Triangle Wave Generator (Highly Linear)

ericgibbs said:

hi iim,
Have you approached a local university to see if their electronic lab would use it as a student project.?
E

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Hi eric,
Ummm....no, I have never thought of it, besides I have not got any proof that it would work

iimagine said:

Thank you ericgibbs and all who have respond to this po


Hi,

I have already considered this before and have come up with a way of doing it. Its a true 1:1 triangle, perfect linear but requires too many components so I abandoned it.
Because a perfect linear 1:1 triangle is not what I am looking for, therefore I like this 7 transistors circuit better
Thanks for your suggestion though

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Hi,

Too many components? The 7 transistor circuit isnt even complete as it stands in the drawing. The circuit i mentioned requires 4 transistors and a few parts, but it's self complete except for the power supply.

What exactly are you looking for here?

MrAl said:

Hi,

Too many components? The 7 transistor circuit isnt even complete as it stands in the drawing. The circuit i mentioned requires 4 transistors and a few parts, but it's self complete except for the power supply.

What exactly are you looking for here?

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Too many components is what I meant in my drawing, as for your 4 transistors proposal, please be realistic, how can you have a transistor be as a current source and act like a switch to discharge at the same time?
And please, to me a transistor is a component, a diode or a resistor is also a component.

iimagine said:

Too many components is what I meant in my drawing, as for your 4 transistors proposal, please be realistic, how can you have a transistor be as a current source and act like a switch to discharge at the same time?
And please, to me a transistor is a component, a diode or a resistor is also a component.

Click to expand...

Hi,

Like this (see attachment). That's a pic of the voltage across the capacitor being charged by the constant current transistor stage that is being turned on and off by a square wave. It's not perfectly linear, but it is not too bad either. You can see when the stage is turned on the capacitor ramps up, when it is turned off it stays flat (no charge or discharge).

The simplest constant current circuit using a bipolar consists of a transistor, two low current diodes, and two 1/4 watt resistors (although 1/8 watters or SM might work too). It can be made to source or sink current.