Hazard warning circuit
Heat-sensitive variable-resistance light socket insert
High frequency ballast circuit
High frequency ballast for a gas discharge lamp
High frequency gas discharge lamp dimming ballast
High intensity lighting circuit
High pressure discharge lamp lighting apparatus
High pressure sodium vapor lamp having D.C. resistive ballast ci
High voltage incandescent lamp with low-pressure Kr/N.sub.2 gas
High-frequency converter for fluorescent lamps using an improved