G4BRICKBASE OPTO 22, G4BRICKBASE Datasheet - Page 20

• Manufacturer Part Number: G4BRICKBASE
• Description: Programmable Logic Controller
• Manufacturer: OPTO 22

Specifications of G4BRICKBASE

• Leaded Process Compatible: No
• Peak Reflow Compatible (260 C): No
• For Use With: I/O Bricks
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Form 859-000511
Careful consideration should be given to the selection
of the proper SSR for driving a given transformer. Transformers
are driven from positive saturation of the iron core to negative
saturation of the core each ½ cycle of the alternating
voltage. Large inrush currents can occur during the first ½
cycle of line voltage when a zero voltage SSR happens to
turn on during the positive ½ cycle of voltage when the core
is already in positive saturation. Inrush currents greater than
10 times rated transformer current can easily occur.
The following table provides a guide for selecting the
proper SSR for a given transformer rating.
All Opto 22 DC controlled SSRs have a control circuit consisting of 1000 ohms in
series with an LED. Since 3 volts is required to turn on any SSR, the maximum current
required is (3 volt - 1 volt) divided by 1000 ohms which equals 2.0 mA. The 1 volt is
subtracted from the 3 volt signal because 1 volt is dropped across the LED. For higher
control voltages, an external resistor can be added in series with the control voltage to
limit the control current. To limit the control current to 2 mA, calculate the external resistor
R
The DC control voltage range is 3–32 VDC. To calculate the control current for any voltage
within the 3–32 VDC range, use the formula:
I
where R
With a 5V control signal,
I
C
C
C
=
=
= 500 (E
E
5 - 1
1000
1000
C
C
C
- 1
= zero.
- 3) where E
All Opto 22 SSRs are designed to drive inductive loads such as solenoid
valves and electromechanical contactors. The built-in snubber in each
SSR assures proper operation into inductive loads. The following table
is a guide in selecting an SSR to drive a solenoid or contactor.
= 4 mA.
C
= the control voltage.
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