K8055 PWM for slow switching

Hi to all!

Is there a circuit that can be used to modify the PWM signal from the K8055?

I need this to give speed control to slow switching pneumatic valves etc by pulsing the valves on and off at a rate determined by the PWM output… the valves can pulse pretty quickly, but not even close to the PWM frequency (23kHz?)

Could equally well use the variable voltage of the Analogue output (0V-5V) to determine the speed if that would work better?

Many thanks and best regards,


Bit more information:

I need to be able to switch a valve on and off fast (but the fastest it will go is 20ms to open, and 39ms to close)

I have available to me a 0V-5V variable signal, or PWM from the K8055

What approach should I take to setting up the pulsed switching signal at a useful frequency?
Should I be looking at creating a completely new pulse using a 555 circuit maybe?

I have been experimenting with a circuit between K8055 and valve to set the pulse using the standard PWM and a simple amplifier circuit, but it isnt working out for me (I guess because the PWM frequency is way too fast…

Any help greatly appreciated as always!!




Maybe you could use digital output and mosfet transistor? you could get pwm in that way, and the switching frequency would me much slower, circuit would be like this:

just where the motor stands, you connect your valve. I think this should work, and you should be able to reach 20 ms switching frequency. Also you will need pull up resistor connecting power source and digital output