IR2153 smps with short circuit protection.
- Thread starter norazmi
- Start date
MyFirstSMPS
New member
If you want you can use this circuit or softstart part only.
I buid this smps and got ~1300 VA power. Conversion Fq is set to 74kHz, transformer is 3C94 from Ferroxcube. Protection circuit work well, input is protected only against overvoltage (MOV, 275V) but output is protected also against overcurrent and short circuit - if current exceeds pre-set limit (seting is done by this 2.2 kilo-ohm potentiometer), then IR2153 shut-down.
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IR2153protected.jpg
Silvio
Well-known member
The circuit looks ok for me but I can see that rectification of the protection circuit only goes in one direction due to the half wave rectification made with a single diode. I think if the short circuit will occur in the opposite direction of the diode it will persists until the next pulse for the scr to trigger, to my believe this may blow the mosfets. Have you taught of this or am I wrong? A current trafo however will monitor both sides of the pulses if it has a full bridge at the output.
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youkito1991
New member
Hi.I have built this smps long ago. It worked but we need to change a bit for the soft start circuit, if it have short-circuited in output at the first time when we turn on the power, the 100 ohm 2W resistor will be hot and blow up. We can replace it with 100 ohm 20W, but this is also a temporary solution. Sorry for my english language
MyFirstSMPS
New member
Hm, I haven´t had this kind of problem.
And protection circuits work well also. But yes, you may replace this resistor with powerful one, it gets hot for some type resistors - I have used it 2W military grade metal film and they last over 5 times more power. I think that 20W wirewound may be good solution.
And protection circuits work well also. But yes, you may replace this resistor with powerful one, it gets hot for some type resistors - I have used it 2W military grade metal film and they last over 5 times more power. I think that 20W wirewound may be good solution.
Silvio
Well-known member
Regarding an SMPS built around an IR2153 has the problem of the secondary soft start. This can be overcomed by using a second relay in the middle of the half bridge thus using a resistor here hooked across the relay contacts as well will eliminate the problem when charging the secondary capacitors.
As far as the short circuit is concerned it can be made with a current transformer either having a centre tapped winding and making a full bridge using two diodes and a classic bridge resistor followed by a pot to set the trip current and pulling either pin 3 or the supply pin 1 using an scr.
Another approach that I used is to use a high frequency startup arrangement by forcing the IR2153 to work at 3 times the operating frequency on startup and then settles down to the operating frequency after a couple of seconds. The circuit is rather simple by putting a second timing capacitor in parallel with the first one using an npn transistor which its base is driven from the centre of the half bridge followed by a small capacitor of around 47uf to give some delay before the npn transistor switches on.
The theory behind this is that the transformer looses a lot of its magnetic flux with the higher frequency due to the number of turns designed for the operating frequency. Tht transformer in return cannot produce the full current hence the output current is limited during start up.
In my 700w smps (published here in diysmps) I used a 160v zener to give time for the primary bulk cups to charge up before enough voltage is present to start up the IR2153. This will pause a little the start up of the IR2153 having a good charge before start up.
Lastly you do not need a 50 or 100 ohm resistor for the initial charge up of the primary capacitor/s usually a 15 to 20 ohm NTC resistor will suffice to limit the inrush current. This will only depend on the input rectifier momentary surge current it can withstand. NTC resistors are very robust if used properly. These are quite cheap from aliexpress.
audio smps 700w tread
http://www.diysmps.com/forums/showthread.php?897-Audio-smps-700w-(IR2153)&highlight=700w+smps
As far as the short circuit is concerned it can be made with a current transformer either having a centre tapped winding and making a full bridge using two diodes and a classic bridge resistor followed by a pot to set the trip current and pulling either pin 3 or the supply pin 1 using an scr.
Another approach that I used is to use a high frequency startup arrangement by forcing the IR2153 to work at 3 times the operating frequency on startup and then settles down to the operating frequency after a couple of seconds. The circuit is rather simple by putting a second timing capacitor in parallel with the first one using an npn transistor which its base is driven from the centre of the half bridge followed by a small capacitor of around 47uf to give some delay before the npn transistor switches on.
The theory behind this is that the transformer looses a lot of its magnetic flux with the higher frequency due to the number of turns designed for the operating frequency. Tht transformer in return cannot produce the full current hence the output current is limited during start up.
In my 700w smps (published here in diysmps) I used a 160v zener to give time for the primary bulk cups to charge up before enough voltage is present to start up the IR2153. This will pause a little the start up of the IR2153 having a good charge before start up.
Lastly you do not need a 50 or 100 ohm resistor for the initial charge up of the primary capacitor/s usually a 15 to 20 ohm NTC resistor will suffice to limit the inrush current. This will only depend on the input rectifier momentary surge current it can withstand. NTC resistors are very robust if used properly. These are quite cheap from aliexpress.
audio smps 700w tread
http://www.diysmps.com/forums/showthread.php?897-Audio-smps-700w-(IR2153)&highlight=700w+smps
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