Here is a simple heater circuit that can be operated from a 12V battery. The first part of the circuit is an astable multivibrator build around the two transistors Q1 and Q2 . The ON time of ...

This close-up through the polycarbonate shows the absorber screen, the foam sealer molding, screws with EPDM washers, battens and a bottom vent. After walking into my workshop one December morning and ...

Article 424 is a nine-part article on fixed electric space heating. Why so much text for what seems to be a simple application? The answer is that Art. 424 covers a variety of applications — heaters ...