SSRs allow the switching of large loads via ultra-sensitive input power. A low level logic signal (TTL) can activate a switch for as much as 100 Amps.
How much current does a solid state relay draw?
Packaged solid-state relays use power semiconductor devices such as thyristors and transistors, to switch currents up to around a hundred amperes. Solid-state relays have fast switching speeds compared with electromechanical relays, and have no physical contacts to wear out.
How do you size a solid state relay?
When selecting a Solid State Relay, consider: Current rating, as a general rule consider using the relay at no more than 70% of its rated current. Electrical environment,. i(In harsh electrical environments, consider a relay with an line voltage rating above the application line voltage.)
What is the minimum current rating of solid state relay?
Solid-state Relays typically have less than 10 mA or leakage current at 200 V. To prevent the leakage current from causing load reset errors, the reset current is estimated to be at least 10% of the rated current, and the minimum load current is specified at 0.1 A.
How is a solid state relay energized?
When voltage is applied to the input of the SSR, the relay is energized by a light-emitting diode. ... In the case of nonzero-voltage crossover relays, the output solid-state switch is turned on at the precise voltage occurring at the time.
How do you trigger a solid state relay?
The SSR is triggered by an external voltage applied across its control terminal. It has no moving parts and thus can operate much more quickly and last longer than a traditional switch. If it uses infrared light as a contact; the two sides of the relay are photo-coupled.
How are solid state relays grouped?
According to the I/O form, the solid-state relays can be divided to four types: DC input-AC output type solid state relays (DC-AC SSR relays), DC input-DC output type solid state relays (DC-DC SSR relays), AC input-AC output type solid state relays (AC-AC SSR relays), AC input-DC output type solid state relays(AC-DC ...25 ene 2021
How does a solid state relay work?
A solid state relay (SSR) is an electronic switching device that switches on or off when an external voltage (AC or DC) is applied across its control terminals. It serves the same function as an electromechanical relay, but has no moving parts and therefore results in a longer operational lifetime.
How do you activate a solid state relay?
To activate or turn “ON” a sold state relay into conduction, a voltage greater than its minimum value (usually 3 volts DC) must be applied to its input terminals (equivalent to the electro-mechanical relay coil). This DC signal may be derived from a mechanical switch, a logic gate or micro-controller, as shown.