The advantages and disadvantages of solid state relay long, advantages, mechanical, function, contact

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1,Advantage
( 1) the high life, high reliability: solid state relay
no mechanical parts, made of solid device to complete the contact function, since there is no movement of the parts, hence the high impact, vibration environment, due to the composition of solid state relay components inherent characteristic, decided the solid state relay and long service life, high reliability. Solid state relay
( 2) has the advantages of high sensitivity, small control power, good electromagnetic compatibility: solid state relay input voltage range is wide, the driving power is low, with most logic integrated circuit compatible without buffer or drive.
( 3) the rapid conversion of: solid state relay because the use of solid state devices, so the switching speed can be obtained from a few milliseconds to a few subtle.

( 4) small electromagnetic interference: solid state relay no input " coil ", no contact arcing and rebound, thus reducing the electromagnetic interference. The majority of output AC solid state relay is a zero voltage switch, at zero voltage zero current turn-on, located off, reducing the current waveform is suddenly interrupted, thereby reducing the switching transient effect.
2, shortcomings
( 1) conducting tube voltage, SCR or two-way silicon controlled positive pressure up to 1~2V, high-power transistor saturation pressure drop in between 1~2V, general power MOSFET on-state resistance than the mechanical contact with large contact resistance.
( 2) a semiconductor device can have a turned off to a few milliamps of current leakage, therefore can not achieve the desired electrical isolation.
( 3) as the tube voltage, conducting power consumption and heat generation is also large, high-power solid-state relays volume is far greater than the same volume of electromagnetic relays, the cost is also high.
( 4) electronic components temperature characteristics and electrical circuit anti-interference ability is poorer, radiation tolerance of solid state relay
Worse, if do not take effective measures, then the work reliability is low.
( 5) a solid state relay on overload has greater sensitivity, must use the fast fuse or RC damping circuit for overload protection. Solid state relay load and environmental temperature was significantly related to, temperature, load capacity will decrease.
(6 ) the main disadvantage is in on-state voltage drop ( needs corresponding cooling measures ), a leakage current, DC is not common, a few other contact group, over current, over voltage and voltage rising rate, the rate of current rise index difference. Reference link legend Mall (http://www.315mro.com )