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Sg3525 Ir2110 Smps Rarest10/27/2021
It is a 16 pin integrated circuit. Even top inverters manufacture companies also use Sg3525 in dc to dc converter part of the inverter. It is used in maximum inverters available in the market. Sg3525 is a voltage mode PWM controller integrated circuit.
![]() Sg3525 Ir2110 Smps Rarest Series Between TheRobin, (who is one of the avid readers of this blog, and a passionate electronic enthusiast):Ok,just to check everything is working I separated the two high side fets from the two low side fets and used the same circuitry as:Connecting the cap negative to the mosfet source then connecting that junction to a 1k resistor and an led to ground on each high side fet.Pin 11 pulsed the one high side fet and pin 14 the other high side fet.When I switched the SG3525 on both fets lit up momentarily and the oscillated normally thereafter.I think that could be a problem if I connected this situation to the trafo and low side fets?Then I tested the two low side fets,connecting a 12v supply to a (1k resistor and an led) to the drain of each low side fet and connecting the source's to ground.Pin 11 and 14 was connected to each low side fets gate.When I switched the SG3525 on the low side fet's would not oscillate until I put a 1k resistor between the pin (11, 14) and the gate.(not sure why that happens).I appreciate your efforts, however that doesn't seem to be the best way of checking the IC 's output response.Alternatively you can try a simple method by connecting individual LEDs from pin#11 and pin#14 of the IC to ground with each LED having its own 1K resistor.This will quickly allow you to understand the IC output response.this could be done either by keeping the full bridge stage isolated from the two IC outputs or without isolating it.Furthermore you could try attaching a 3V zeners in series between the IC output pins and the respective full bridge inputs.this will ensure that false triggering across the mosfets are avoided as far as possible. In this situation the following things happen withing the left side BC547 stage:1) The 10uF capacitor charges up via the 1N4148 diode and the low side mosfet connected with its negative terminal.2) This charge is temporarily stored inside the capacitor and may be assumed to be equal to the supply voltage.3) Now as soon as the logic across the SG3525 reverts with the subsequent oscillating cycle, the pin#11 goes low, which instantly switches OFF the associated BC547.4) With BC547 switched OFF, the supply voltage at the cathode of the 1N4148 now reaches the gate of the connected mosfet, however this voltage is now reinforced with the stored voltage inside capacitor which is also almost equal to the supply level.5) This results in a doubling effect and enables a raised 2X voltage at the gate of the relevant mosfet.6) This condition instantly hard triggers the mosfet into conduction, which pushes the voltage across the corresponding opposite low side mosfet.7) During this situation the capacitor is forced to discharge quickly and the mosfet is able to conduct only for so long the stored charge of this capacitor is able to sustain.Therefore it becomes mandatory to ensure that the value of the capacitor is selected such that the capacitor is able to adequately hold the charge for each ON/OFF period of the push pull oscillations.Otherwise the mosfet will abandon the conduction prematurely causing a relatively lower RMS output.Well, the above explanation comprehensively explains how a bootstrapping functions in full bridge inverters and how this crucial feature may be implemented for making an efficient SG3525 full bridge inverter circuit.Now if you have understood how an ordinary SG3525 could be transformed into a full fledged H-bridge inverter, you might also want to investigate how the same can be implemented for other ordinary options such as in IC 4047, or IC 555 based inverter circuits, ….think about it and let us know!UPDATE: If you find the above H-bridge design too complex to implement, you may try a much easier alternativeSG3525 Inverter Circuit which can be Configured with the the above Discussed Full Bridge NetworkThe following image shows an example inverter circuit using the IC SG3525, you can observe that the output mosfet stage is missing in the diagram, and only the output open pinouts can be seen in the form of pin#11 and pin#14 terminations.The ends of these output pinouts simply needs to be connected across the indicated sections of the above explained full bridge network for effectively converting this simple SG3525 design into a full fledged SG3525 full bridge inverter circuit or an 4 N channel mosfet H-bridge circuit.Feedback from Mr. Circuit DiagramReferring to the above diagram, we can identify the four mosfets rigged as an H-bridge or a full bridge network, however the additional BC547 transistor and the associated diode capacitor looks a bit unfamiliar.To be precise the BC547 stage is positioned for enforcing the bootstrapping condition, and this can be understood with the help of the following explanation:We know that in any H-bridge the mosfets are configured to conduct diagonally for implementing the intended push pull conduction across the transformer or the connected load.Therefore let’s assume an instance where the pin#14 of the SG3525 is low, which enables the top right, and the low left mosfets to conduct.This implies that pin#11 of the IC is high during this instance, which keeps the left side BC547 switch ON.
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