I'm building a signal generator for my electronics project, and to generate the triangle wave, we're required to use a relaxation oscillator (we can add other circuits around it to improve the quality, but the minimum is to use the relaxation oscillator).
\$R\$ is a pot (\$8\Omega\$ to \$51k\Omega \$),
\$R_1 = 1k\Omega\$,
\$C\$ is selected using a dip switch depending on the desired frequenecy range:
- \$6.8\mu F \$ for 18Hz to 1.1kHz
- \$0.1\mu F \$ for 1.2Hz to 61kHz
- \$27 nF \$ for 4.5kHz to 200kHz
Op-amp : Data sheet
Supply voltage : \$\pm 15 \ V \$
2x Electrolytic decoupling capacitors : \$100\mu F \$
At low frequencies, the oscillator produces a very nice triangle wave, but at higher frequencies, there's noise that appears at the peaks.
Anyone know what could be causing this, and what I could add to clean it up?
We're not allowed any dedicated ICs, except for Op-amps.