RDK-91 Power Integrations, RDK-91 Datasheet - Page 35

• Manufacturer Part Number: RDK-91
• Description: KIT DESIGN REF TINYSWITCH-III
• Manufacturer: Power Integrations
• Series: TinySwitch®-IIIr

Specifications of RDK-91

• Main Purpose: AC/DC, Primary Side
• Outputs And Type: 1, Non-Isolated
• Power - Output: 12W
• Voltage - Output: 12V
• Current - Output: 1A
• Voltage - Input: 85 ~ 265VAC
• Regulator Topology: Flyback
• Board Type: Fully Populated
• Utilized Ic / Part: TNY274, TNY275, TNY276, TNY277, TNY278, TNY279, TNY280
• Product: Accessories & Kits
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency - Switching: -
• Other names: 596-1194

17 OVP Operation Verification
While the RD-91 is in normal operation, monitor the output with a storage oscilloscope.
To cause an overvoltage condition to occur, short circuit the optocoupler LED (as shown
below) to open the feedback control loop.
voltage rising until the increasing voltage across VR2 causes it to conduct, and the
TNY278PN device latches off. To reset the OVP latch, the AC input power must be
removed long enough to allow the input bulk capacitors to fully discharge.
Page 35 of 37
Figure 33
–
Point on PCB to Apply Short Circuit to Trigger OV Shutdown.
Short these points to
test OVP functionality
The oscilloscope will capture the output
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