THE PROTECTION OF HIGH-VOLTAGE CIRCUITS OF RADIOELECTRONIC APPARATUS FROM CURRENT OVERLOADS

One of the most important problems that arises when using high-power e lectron devices is to protect the power supplies and the electron devi ces from damage due to internal breakdown. The reliability and life of the most complex radio-electronic apparatus depend on the effectivene ss of this protection. There is a large variety of circuits for protec ting electron devices. The simplest of these contain a current relay i n the low-voltage circuit of the power supply and a contractor which d isconnects the step-up transformer of the power supply from the supply lines when overloads occur. In the most up-to-date systems a current pickup is connected directly into the power supply circuit of the elec tron device, which is kept at a high potential. Here circuits at diffe rent potentials are decoupled from one another by means of a high-volt age transformer [1] or lightguides [2, 3]. The low operating reliabili ty of optoelectronic devices decoupled in this way in on-board and por table apparatus has given rise to the development of basically new dev ices, namely, interface relays based on gerkotrons (hermetically seale d relays) [4] and systems for protecting electron devices based on the m [5, 6]. A large number of circuit methods of protecting electron dev ices developed by leading foreign companies (Siemens, Telefunken, Gene ral Electric, etc.) are considered in [7]. These circuits are based on the use of current-limiting components (for example, coils) in the su pply circuits of the electron devices, and also on controllable high-v oltage dischargers (thyratrons and ignitrons) which shunt the electron device. Thyristor, transistor, and hybrid gerkon-semiconductor switch es for electron-device protection systems are considered in [8, 9].