Hi guys, I have a little problem..
I made class D 200W RMS amplifier from Ejtagle from Faros de Electronica. I made 2 chanels for full bridge with phase inverter with TL072.
Output mosfets are IRF9540N and IRF540N. Amplifier is amasing and very powerfull, it has very strong bass too, and I like it very much but when I conected in full bridge, 100-200W before full power amp start to distord a little, then DC protection starts and raley disconect speaker.
I use +-40V and simple Led Vu meter for cliping indication calibrate on 26VAC on output on 1KHz sine.
In half bridge amp works fine even in full cliping but when I push in hard cliping DC protection starts.
Output Inductor: 2 x 106-2 for each amp
35uH + 1.5uF - has best results and biggest power
35uH + 1uF - little lower power before DC protection
35uH + 470nF - lower power then previous option
35uH + 220nF - the worst results, DC prot starts on 100-200W
22uH + all of these caps - Same results like before
47uH + all of these caps - Coil burning and go to smoke
On same core with inverted pahse results are the same.
I notice that WIHOUT speaker on 1KHz sine DC protection starts on 30VAC, 15KHz sine, DC prot start on 70V on 35uH+220n and that DC prot strats on lower volatge when I increase cap value (on example on 35uH+1uF 1KHz sine-DC prot starts on 27VAC, 15KHz sine-DC prot starts on 55VAC)
DC offset is 20mV on stand by mode without input signal
Problem is output inductor, maybe core go to situration on big current and produce DC voltage. When DC prot starts, DC voltage on output is 1V to 15V, I cant measure right value, digital multimeter is going creazy, and values are diferent all the time.
When relay disconect speakers, I hear somtng like Bzzzzzzz in inductor caps or output mosfets, cores are cold and dont hear enything form it.
On 4R load power is lower before DC prot then on 8R. Because of that I think that cores go to situration, i dont know..
What can I do, maybe go with bigger core like 130-2, I don know
I realy like this amp and I have to make it 😀
Thanks if someone helps me 😉
In attachments are original file form owner and to him inductor have to be 30-35uH + 640n
I made class D 200W RMS amplifier from Ejtagle from Faros de Electronica. I made 2 chanels for full bridge with phase inverter with TL072.
Output mosfets are IRF9540N and IRF540N. Amplifier is amasing and very powerfull, it has very strong bass too, and I like it very much but when I conected in full bridge, 100-200W before full power amp start to distord a little, then DC protection starts and raley disconect speaker.
I use +-40V and simple Led Vu meter for cliping indication calibrate on 26VAC on output on 1KHz sine.
In half bridge amp works fine even in full cliping but when I push in hard cliping DC protection starts.
Output Inductor: 2 x 106-2 for each amp
35uH + 1.5uF - has best results and biggest power
35uH + 1uF - little lower power before DC protection
35uH + 470nF - lower power then previous option
35uH + 220nF - the worst results, DC prot starts on 100-200W
22uH + all of these caps - Same results like before
47uH + all of these caps - Coil burning and go to smoke
On same core with inverted pahse results are the same.
I notice that WIHOUT speaker on 1KHz sine DC protection starts on 30VAC, 15KHz sine, DC prot start on 70V on 35uH+220n and that DC prot strats on lower volatge when I increase cap value (on example on 35uH+1uF 1KHz sine-DC prot starts on 27VAC, 15KHz sine-DC prot starts on 55VAC)
DC offset is 20mV on stand by mode without input signal
Problem is output inductor, maybe core go to situration on big current and produce DC voltage. When DC prot starts, DC voltage on output is 1V to 15V, I cant measure right value, digital multimeter is going creazy, and values are diferent all the time.
When relay disconect speakers, I hear somtng like Bzzzzzzz in inductor caps or output mosfets, cores are cold and dont hear enything form it.
On 4R load power is lower before DC prot then on 8R. Because of that I think that cores go to situration, i dont know..
What can I do, maybe go with bigger core like 130-2, I don know
I realy like this amp and I have to make it 😀
Thanks if someone helps me 😉
In attachments are original file form owner and to him inductor have to be 30-35uH + 640n
Hi you sent me a PM.
I had a quick look at your schematic and don't understand how it works at all so sorry I cant be much help.
I had a quick look at your schematic and don't understand how it works at all so sorry I cant be much help.
Tnx Nigel...
Tell me, is it possible that i need stronger core?
Is it possible that 106-2 siturates at high power and produce dc voltage?
Tell me, is it possible that i need stronger core?
Is it possible that 106-2 siturates at high power and produce dc voltage?
What can cause situration of the core? Maybe high freq? Freq is about 400khz...
Is it situration of the core after all?
Is it situration of the core after all?
I ran mine at 400KHz with no problems but settled for 250KHz in the end.
Shoot through can be a cause of over heating.
If the coil is being destroyed have you used to thin wire ?
Shoot through can be a cause of over heating.
If the coil is being destroyed have you used to thin wire ?
I used 4 x 0.4 wire.
On 35uH coil is cold, heatsink too.
I will put diodes 1N4007 from out to ucc+ and ucc-. That maybe descrise ripple current and i just found out that i have wrong conection when i use same core. I conect inversed two windings and i should conected in paralel because signal goes from out+ to out- automaticly coil will be in different phase.
What do you think about diodes and this for core?
Tnx
On 35uH coil is cold, heatsink too.
I will put diodes 1N4007 from out to ucc+ and ucc-. That maybe descrise ripple current and i just found out that i have wrong conection when i use same core. I conect inversed two windings and i should conected in paralel because signal goes from out+ to out- automaticly coil will be in different phase.
What do you think about diodes and this for core?
Tnx
1N4007 are 1A regular (slow) diodes.
Use schottkey or fast rectifiers with higher current rating.
FWIW there are already diodes in your FET's.
Use schottkey or fast rectifiers with higher current rating.
FWIW there are already diodes in your FET's.
Bear in mind when you bridge the amplifier the speaker impedance should be doubled or you will take twice as much current.
So if you used 4 ohms half bridge you should use 8 ohms full bridge.
So if you used 4 ohms half bridge you should use 8 ohms full bridge.
But i want 4 ohms in full bridge for bigger power, this amp can handle 2 ohms, tested in half bridge...
I try with diodes, without changes 🙁
I try with diodes, without changes 🙁
- Status
- Not open for further replies.