Unlike mechanical relays this circuit has a practically infinite duration, requires only 5 Milli Ampere of pilotage, has exceptional insulation and is very small. Also the spare PhotoMOS can be easily replaced on the base, also with different models and possibly also with the economical PhotoTRIAC, which withstand high voltages but can only be used in AC.
The input connector is a 3-pole, in order to follow the thereminic standard which provides + 5Volt on the central pole. But in this circuit the +5 Volt is not used, then you can use two single cables Dupont for signal and to GND.
If you have to drive multiple forms together, you could combine the Central Server with GND, with a spot of solder on the bottom of the print. That way you could carry only one bulk cable (GND) and then use the Central Server to bring mass to neighboring modules.
Should the input be piloted with voltages higher than 5 Volt would be enough to add a resistor in series to the signal.– For 12 Volt the resistor will be from 1500 or 1800 ohm resistor, 1/4 or 1/8 Watts.– For 24 Volt the resistor will be from 3300, 3900 or 4700 ohm resistor, 1/4 Watts.
This project is lucky. It concerns to the Chinese for automating machines screw-setting machines they use in production, then takes precedence over many other, It will be produced in record time and will soon be available on Store-Ino,
STL files are also available to print a plastic support for a form opto-relays or for four modules opto-relays.
Why use PhotoMOS instead of mechanical relays?Mechanical relays cost ten times less and bearing currents and voltages above, but they last Sun 200, 000 operations. Might seem to many, but doing the math you may have some surprises. In a case of example (We're designing a car wrench), There are two relays that switch twice every six seconds. If the machine makes production 24 hours on 24, How long will the relay? Maybe a few years? Wrong, each week will be both faults. Since then the production machines are five, and soon to be ten, probably every day there would be one or two under repair. That's why, in some cases, You can't use the mechanical relays.
Why not simply use a Mosfet or Darlington?In this same page, some current projects show even greater bearing adapters and cost less. In some cases you may use them, but only a photo-MOS can give complete safety, to completely isolate the logic, from electrical disturbances caused by heavy loads, especially if inductive loads.
Types of connectionsDepending on the connection, you get a relay for AC or DC. With the connection “C”, usable only in “DC”, you get a doubling of the maximum current.
The currents and voltages listed in this table are the maximum bearable. To be on the safe side it is good to keep lower than at least one 30%. If you plan to use frequent switching (beyond the 20 Hz) It is good to be limited even further (see the graphs in data sheet).
If driving inductive loads in DC (Transformers, solenoids and motors), each load must have the diode for over-voltage in parallel.
If driving inductive loads in AC (Transformers, solenoids and motors), each load must be in parallel, the suppressor for over-voltage silicon (Transzorb). To achieve an effective protection, the Transzorb must have the correct voltage and current characteristics.
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