Variable Period Full Wave Ssr ( Vpfw Ssr ) - Brainchild BTC-2500 User Manual

5 2 Variable Period Full Wave SSR ( VPFW SSR )

5 2 Variable Period Full Wave SSR ( VPFW SSR )
VPFW SSR is a variable period full wave solid-state relay. It can provide a zero VPFW SSR is a variable period full wave solid-state relay. It can provide a zero
cross output with superior controllability compared to a conventional SSR with cross output with superior controllability compared to a conventional SSR with
a fixed time base. The block diagram of VPFW SSR is shown as follows: a fixed time base. The block diagram of VPFW SSR is shown as follows:
AC AC
Input Input
Pulsed Voltage Pulsed Voltage
Control Input Control Input
Unlike a conventional SSR, the VPFW SSR always give the output an even number of Unlike a conventional SSR, the VPFW SSR always give the output an even number of
half cycles ( full wave ) as shown in the following diagram. half cycles ( full wave ) as shown in the following diagram.
VPFW SSR VPFW SSR
Control Input Control Input
Power Input Power Input
Power Output Power Output
The VPFW switches the load without DC current, hence minimize the harmonic The VPFW switches the load without DC current, hence minimize the harmonic
current and stress on the load. The load life is prolonged. current and stress on the load. The load life is prolonged.
As the duty cycle ( ie. output power level ) of the control input is small, the off As the duty cycle ( ie. output power level ) of the control input is small, the off
period will be extended to keep the output resolution so that the conversion period will be extended to keep the output resolution so that the conversion
error is minimized. As low as 0.1% of timing error can be achieved. Hence, error is minimized. As low as 0.1% of timing error can be achieved. Hence,
VPFW SSR is particularly suitable for a smoother control. VPFW SSR is particularly suitable for a smoother control.
84
AC AC
Output Output
+
Conventional SSR Conventional SSR
UM25001C
Figure 5.2 Figure 5.2
Block Diagram of VPFW SSR Block Diagram of VPFW SSR
Figure 5.3 VPFW SSR Figure 5.3 VPFW SSR
vs. Conventional SSR vs. Conventional SSR
NOTES:
1.The VPFW SSR can be used to drive 1.The VPFW SSR can be used to drive
resistant load and some types of resistant load and some types of
inductance load such as relay, inductance load such as relay,
contactor, magnetic switch, solenoid contactor, magnetic switch, solenoid
valve etc. However, it valve etc. However, it can not drive can not drive
Motor and Capacitance Load. Motor and Capacitance Load.
2. Only 2. Only AC power AC power can supply VPFW can supply VPFW
SSR, otherwise, it will not operate SSR, otherwise, it will not operate
properly. properly.