15 V FOR VTVM

Description: A simple rectifier circuit replaces the battery in a vacuum-tube voltmeter (VTVM). It provides good regulation and eliminates the need for frequent battery replacement. The battery should be removed before using the supply. The AC source can be the 6.3-V secondary of a filament transformer or the terminals of a 6.3-V pilot lamp in any AC equipment. -P. Alexander, Battery Replacement Circuit for VTVM, QST, Jan. 1976, p 42-43.

The rectifier circuit designed for the vacuum-tube voltmeter serves as an efficient alternative to traditional battery power sources. This circuit typically consists of a transformer, rectifying diodes, and filtering capacitors. The transformer steps down the AC voltage from a higher level to the required 6.3 V, which is essential for operating the VTVM.

The rectification process is achieved using diodes configured in a bridge arrangement, allowing for full-wave rectification. This approach improves the output voltage regulation and minimizes ripple, ensuring stable performance of the voltmeter. The filtering capacitors smooth the rectified output, further enhancing voltage stability across varying loads.

In practical application, prior to connecting the rectifier circuit, it is crucial to remove any existing battery from the VTVM to prevent potential damage or malfunction. The circuit can be powered by either the secondary winding of a filament transformer or by tapping into the 6.3-V terminals of a pilot lamp found in various AC-powered equipment. This versatility makes the circuit suitable for a wide range of applications, providing a reliable and maintenance-free power solution for vacuum-tube voltmeters.

Overall, this simple rectifier circuit not only extends the operational life of the VTVM by eliminating the need for frequent battery replacements but also ensures consistent performance through effective voltage regulation.Simple rectifier circuit replaces battery in vacuum-tube voltmeter. Provides good regulation and eliminates need for frequent battery replacement. Remove battery before using supply. AC source can be 6. 3-V secondary of filament transformer or terminals of 6. 3-V pilot lamp in any AC equipment. -P. Alexander, Battery Replacement Circuit for VTVM, QST , Jan. 1976, p 42-43.