Hi
I need to produce a sinusoidal or triangular oscillation with a period of around 30-60 minutes. The circuit needs to be simple and have a low component count, and it's running off batteries (4.5V) so single supply would be best. Quadrature output would be ideal but if not then I can just use an inverter to get the quadrature signal.
I looked at using the typical opamp triangle wave generator or sinusoidal generator but so far they do not seem to be working. I think the resistor values for such a low frequency are too high. I am simulating in LTSpice at the moment, although it is late so it is possible I am not thinking straight and missing something.
Could somebody advise on a circuit that could do this? I basically want to build a light which fades from white to red and back to white over a period of around 1 hour. I will be using LED's for the lighting but don't want to use PWM as the lights will will be filmed and I do not want flickering on the video.
I would appreciate any advice.
I need to produce a sinusoidal or triangular oscillation with a period of around 30-60 minutes. The circuit needs to be simple and have a low component count, and it's running off batteries (4.5V) so single supply would be best. Quadrature output would be ideal but if not then I can just use an inverter to get the quadrature signal.
I looked at using the typical opamp triangle wave generator or sinusoidal generator but so far they do not seem to be working. I think the resistor values for such a low frequency are too high. I am simulating in LTSpice at the moment, although it is late so it is possible I am not thinking straight and missing something.
Could somebody advise on a circuit that could do this? I basically want to build a light which fades from white to red and back to white over a period of around 1 hour. I will be using LED's for the lighting but don't want to use PWM as the lights will will be filmed and I do not want flickering on the video.
I would appreciate any advice.