L.V. Nedro – Leading Engineer, JSC «Concern «VEGA». E-mail: email@example.com
A.V. Spirin – Engineer, JSC «Concern «VEGA». E-mail: firstname.lastname@example.org
Appearance of thyristor effect negatively effects on performance of equipment composed of components made in CMOS technology. Partial or complete refusal of any node equipment can disable the whole complex. It is advisable to apply a functional protection device, which based on power tripping of as well separate units, as products in general, for protection from thyristor effect. The following requirements imposed to functional protection device: it must not contain CMOS elements; applicable element base must be resistant to thyristor effect; the trip command must be issued as a rectangular pulse of positive polarity and short duration (about 3 us).
Integration of protection device in power supply board is the best option of protection the synchronization and commutation device form the thyristor effect. Wherein offered the option of two-channel device of protection on bipolar transistors, comprising a sensor responsive to special effects and a buffer stage representing an emitter repeater and pulse shaper.
As a radiation sensor for sensitivity improvement of protection device, large square p-n junction is usedю The voltage pulse forms on an input resistor, connected in series with p-n junction, it is a signal for pulse shaper which forming a rectangular pulse. The pulse is applied to a mechanical relay or to a key circuit, disposed in each block of equipment or arrives to the whole equipment control circuit.
The relay turns off power of blocks by the pulse leading edge leading edge and switching on – by rеаr. Key circuit transistors works at cutoff mode and does not affect the operation of blocks and equipment. On admission a pulse transistors move in saturation mode, shunting the whole power.
Application of two-channel protection device allows to increase reliability and durability of the device to special effects. To the unauthorized shutdowns of power prevention is required application of the functional protection device, where impulses from two pulse shapers arrive at coincidence circuit, which turns off power of equipment.