Hello
I'm trying to build a rectifier to power our IoT device which would be deployed in the field where there is no DC voltage available. I only have a 120VAC power supply.
I'm using bridge MDB6S to rectifier the AC voltage. Please refer to the attached picture for the circuit diagram. Then I'm using voltage divider to get 15V across the load resistor. The voltage divider is between 30K and 4.7K. The smoothing capacitor is connected across the 4.7K resistor.
https://www.digikey.com/product-detail/en/on-semiconductor/MDB6S/MDB6SFSCT-ND/3137112
When I don't connect anything to the load resistor (4.7K), I measure 15V by a multimeter.
But when I connect our device across the load resistor, it only reads 7.8V. The device pulls 0.3 to 0.4 A of current. Keeping this in mind, I now connected a 470uF capacitor across the load resistor (4.7K). It still does the same.
Any suggestions?
Mod eidt: Direct to mains / transformerless power supply schematic deleted - JohnInTX
I'm trying to build a rectifier to power our IoT device which would be deployed in the field where there is no DC voltage available. I only have a 120VAC power supply.
I'm using bridge MDB6S to rectifier the AC voltage. Please refer to the attached picture for the circuit diagram. Then I'm using voltage divider to get 15V across the load resistor. The voltage divider is between 30K and 4.7K. The smoothing capacitor is connected across the 4.7K resistor.
https://www.digikey.com/product-detail/en/on-semiconductor/MDB6S/MDB6SFSCT-ND/3137112
When I don't connect anything to the load resistor (4.7K), I measure 15V by a multimeter.
But when I connect our device across the load resistor, it only reads 7.8V. The device pulls 0.3 to 0.4 A of current. Keeping this in mind, I now connected a 470uF capacitor across the load resistor (4.7K). It still does the same.
Any suggestions?
Mod eidt: Direct to mains / transformerless power supply schematic deleted - JohnInTX
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