Pulse Width Modulation (PWM or PDM) Circuits

[steve_qix]

Here is the simplified, high quality Pulse Width Modulation (PWM) generator. This PWM generator may be used to drive any pulse modulator, tube or solid state, which accepts a standard TTL input.

The generator includes an anti-aliasing (audio low pass) filter, negative peak limiter and carrier level controls. The generator uses two ICs, and is fairly easy to build. The switching frequency of this generator is 110kHz.

[steve_qix]

This pulse width modulator output section accepts a standard TTL input from a PWM generator, and is capable of modulating transmitters running up to 22 amperes of drain current at 45V (carrier). A single 125V to 135V supply is required.