# Single supply triangular wave generator

#### Samuel Wong 1

Joined Jun 4, 2018
6
Hi guys, I am having a little problem designing a triangular wave generator with a single supply. I intend to use a Schmitt Trigger Comparator circuit and an inverting integrator to design the circuit.
• Duty cycle = 0.5
• Frequency = 8.5kHz
• Supply voltage = 12 V (single supply operation)
• Vmax = 7.3V
• Vmin = 3.1V
All I know for now is the UTP = 7.3V and LTP = 3.1V.
I think I need an negative input for the inverting integrator for it to have a positive gradient part of my triangular wave. Is there any other way to do it?

Any help is appreciated. Thanks!

#### atferrari

Joined Jan 6, 2004
4,110
Exactly what is the little problem?

#### crutschow

Joined Mar 14, 2008
25,632

#### Samuel Wong 1

Joined Jun 4, 2018
6
Exactly what is the little problem?
I need an negative voltage input for the inverting integrator for it to have a positive gradient part of my triangular wave. However, I am only allowed to use a single 12 volt supply.

I have not built the circuit as I am still in the process of designing the circuit and also deciding value of components.

#### atferrari

Joined Jan 6, 2004
4,110
Please post a copy (verbatim) of the problem as it was given to you.

#### crutschow

Joined Mar 14, 2008
25,632
You can design one without a negative supply.
You just apply a plus voltage offset to the plus input of the integrator using a resistive divider.

#### atferrari

Joined Jan 6, 2004
4,110
Please post a copy (verbatim) of the problem as it was given to you.
Thanks so much Samuel for ignoring my request.

#### Papabravo

Joined Feb 24, 2006
14,655
Thanks so much Samuel for ignoring my request.
Apparently this is the place for bad relationships.

#### crutschow

Joined Mar 14, 2008
25,632
Do you have the formulas or equations to find out the values of components?
The reference that Bertus posted has some equations.

But it would be a good exercise for you to determine that yourself.
You don't learn much from simply copying a circuit.