Sometimes in radio Amateur practice problems with commutation powerful network loads. Examples include nodes switching to reversing three-phase motors, starting devices of different machines, water heaters etc., electro-mechanical switches for some technical characteristics no longer meet modern requirements.
To solve such problems allow optosymistor switches. Control switch, usually using low-power optosimistory that include powerful thyristors. Scheme one of variants of such a switch, designed for multiple independent loads shown in Fig. 1. To the control input of the constant voltage is served 4,6 V. Maximum control current of one channel of 30 mA. The maximum current the gate electrode powerful triac VTA41-800A equal to 50 mA, and the load current can reach 40 A.
Fig. 1
The number of channels of the switch is limited only by the capacity of the voltage source management. HL1 led indicates that the channel is enabled, and HL2 - connected load to the channel and working properly powerful triac VS1.
Optimistiniu the switch has a number of advantages over mechanical switches. The presence of galvanic isolation between low-voltage circuit the control and power circuits electrical safety use device and the remote control options, including using computer. There are no restrictions on the configuration of switched loads. The device can easily be adapted to work with loads of different power.
A source of control voltage can serve as a simple power supply, assembled according to the scheme in Fig. 2. Management conclusions 2 all channels are combined in common wire, and pin 1 is connected to the power supply in series with each the toggle switch. The switching of the switches serves network, the voltage at a particular load. Tumblers suit any until thin. WDM-08.
Fig. 2
A source of control voltage can be made of any unregulated network adapter by adding a stabilization circuit of the resistor R1 and a Zener diode VD5. The voltage winding II of the transformer T1 may be within 7...15 V is required only to provide the optimum current through the Zener diode VD5 the selection of resistor R1.
The switch can be used optosimistory. MOS-MOS, MOS-MOS (the maximum control voltage is 6 V, the current control from 5 to 30 mA, depending on the type). Instead VTA41-800V, depending on the specific load, suitable powerful triacs BTA-600 (current up to 12 A), VTA41-800 I. VTA41-600 (40 A) with any alphabetic indices or domestic TC series 122 (20 and 25 (A), TS (40 and 50 A) TS (63 and 80 A) for a voltage of less than 600 V. the Diodes KDA replace any of the series KD521 and KD522, as well as imported 1N4148.
Author: G. Gadzhiev