I need some suggestions on creating a power supply that is capable of varying voltage from near zero to 120vac at about 3A and is capable of accepting a milliamp signal from a controller IC. I need a very quick response time for partial load to full load voltage. This is for varying the voltage on an electrical resistance heater coil that has to maintain a set airflow temperature through a tube. As the airflow varies from none to high flow, the coil voltage has to continuously adjust to maintain the temperature set point and to avoid damaging the coil when the airflow is minimal. ie... low airflow, low coil voltage; high airflow, high coil voltage. Any help would be greatly appreciated. Thank you.
Alex
Alex