Marconi Instruments Limited

Victor F Arnold

Roger C Dixon

A combined frequency and modulation measuring instrument contains a frequency counter which provides a direct indication of a carrier frequency and which is used to control the frequency of a local oscillator by means of which a modulated carrier frequency is converted directly to a required intermediate frequency.

Electrical test instruments

A protection circuit suitable for use with electronic test equipment contains a switch which is open circuited if an overload condition is detected. The opening of the switch isolates the overload detector from the applied overload thereby allowing the detector to have a relatively low power handling capability. If the switch is manually closed whilst the overload condition persists the switch is automatically re-opened within a short predetermined time.

Growing community of inventors

St. Albans, United Kingdom

Victor F Arnold