That is a totem pole driver. On a positive pulse, the npn opens, charges the gate(s), and when the pulse is off or negative, the pnp opens and drains the gate(s). When working the gates at high frequencies, like spwm with carriers in the tens or hundreds of khz, that little capacitance in the gates can require huge currents to fill and drain, therefore some beefier bipolars inserted between the ir21xx (which can peak 2A as an absolute maximum) and the gates. Also, more parallel fets equals higher total gate capacitance. Not putting enough current in the gates to charge and drain them will leave the fets in the ohmic region for *time and blow them to shards as they can't handle the tdp.
@bjtaudio
3 жыл бұрын
The gnd reference is on the other side of the shunt, so no DC noise and voltage drop is introduced onto the mosfet gates with the drive signal. 104 is in picofarads = 0.1uF or 100nF plus the 12V supply on the high side mosfet bank is not the same 12V on the low side as it must be isolated via the dc to dc converter as its high side referenced.
@yancymuu4977
2 жыл бұрын
I believe the high side circuit is a bootstrap as well as a driver circuit. It is needed because the voltage on the high side mosfet gates must be 12 volts greater than the input battery voltage, on the emitter for the device to conduct.
@kresimirpecar4925
6 жыл бұрын
I think this is high side and low side drivers for mosfets but in discrete version to keep cost low
@MrManolismo
3 жыл бұрын
tip41C on your diagram will not work because the collector has no dc bias voltage relative to both the base and emitter. bipolar device needs dc bias before is works, like forward and reversed biasing scheme. Maybe that schematic portion well works only because of leakage in the capacitors
@lvmrevolutiondotinfo6421
3 жыл бұрын
i have on the gate of alternating output AC 1700v and not 24v as i would think since the system is powered at 48v. how can i solve?
@jboy4real
Жыл бұрын
How do calculate the number of mosfets to use in your design.thanks
@gamvin2107
5 жыл бұрын
Those transistors were configure as a push pull.The capacitors at the high side are boost capacitors and the diode is a boost diode.It is nothing but a buffer to drive more mosfets in parallel.
@sasanka41
3 жыл бұрын
@Joel Clemens do you have any schematics of the pcb you are using as I couldn't find any schematic or datasheet for that pcb.
@erroneus
3 жыл бұрын
Sorry no, had to reverse engineer to do any repairs.
@sasanka41
3 жыл бұрын
@@erroneus Is it possible for you to reverse engineer the circuit an provide me with a schematic of the overload and low battery protection circuit of that PCB. Thank you very very much
@salmanahmed9464
5 жыл бұрын
Basically they add totem pole circuit to drive mosfet bank
@bjtaudio
5 жыл бұрын
The 0.1 inch pitch KK connectors will work with mains voltage provided its fused, but it's not best practice, it more the pcb track creep-age distances that are the issue, 0.2 inch should have been used. A simple trick is to use a 3 way but omit the middle pin and pad to maintain good clearance between A and N.. The Inductor is far too small for 150A, as it should only get warm not hot and it may also be saturating the core which may explain the rough wave form as more power is pulled. I'm not happy with the power supply decoupling either, as the ripple current is big and caps are far too small for 150amps continuous, it will go pop! Need to get a scope and be sure there is sufficient dead time, and the diver circuit is switching the mosfet on and off fast enough, or you guest it it will also go pop! it can be very frustrating and expensive, I question that driver circuit, as it may not be driving the mosfet gates hard enough That gate resistor and diode is not the best idea either as the slower the slew rate the more power is wasted. I think what is happening the inductor is saturating and switching voltage spikes are exceeding the mosfets V-D-S voltage which is only 80V, I feel 100V mosfets should have been used.
@xierxu
4 жыл бұрын
Still confussed as duck. Can you draw a full schematic?
@neikesd
5 жыл бұрын
hi Joel i bought a board like this one i blew the RO resister by the dc buck shorted the on switch! can you tell me the value of it or where can i get a schematic
@erroneus
5 жыл бұрын
i'm not sure which resistor you are talking about. Can you post a photo somewhere? I couldn't get a full schematic from the supplier, but the design is pretty simple.
@neikesd
5 жыл бұрын
Joel Clemens I can send a pic my email is dneikes99@gmail.com. Thanks for responding. I’m learning the hard way lol
@gioraver
5 жыл бұрын
great explanation
@JohnHeath777
5 жыл бұрын
Where you get this board?
@erroneus
5 жыл бұрын
Aliexpress. There should be a link in the description of this or one of my other videos
@therider3939
4 жыл бұрын
104 its 100 nano farads
@huntleywhite1220
5 жыл бұрын
go to the back shed forum building a inverter from scratch that forum help me to put together a powerful inverter it will give you some insight on these board
Пікірлер: 25