Self-oscillating class D amplifier

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Congratulations! well done! :)
I do not understand, why there can appear 3V at amp output appear, but it makes no sense anymore, since you solved the problems with POP and startup ;)
Thanks! I am very glad :)
I think it is needed to generate the shutdown signal for IR2110 driver. For example, if the -V source is less than 15-20 Volts, then generate shutdown. If you need an example circuit for it, I try to paint :)
Probably problem of deenergizing arises because of different speed of recession of feeding pressure for the amplifier and the separate stabilizer on 12V for the driver and logic, it would be interesting to see your variant of the scheme of deenergizing of the driver, it is possible on contact@svpremvs.cc
Well, if you want to experiment with it, just do it! :) Theoretically it will work, but practically there are usually a lot of issues... :rolleyes:
Experiments only have begun :devilr:
I suggest, that you try to paint the schematic for unipolar amp yourself first, and I will try to find errors then ;)
The scheme for a unipolar PSU I will draw a bit later, I can send to you on usual email.
 
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it would be interesting to see your variant of the scheme of deenergizing of the driver

It is not needed to deenergize the driver, it is needed to shutdown it, using SD pin of IR2110.

Experiments only have begun :devilr:

Do not broke too much of mosfets, otherwise experiments will be too expensive ;)

The scheme for a unipolar food I will draw a bit later, I can send to you on usual email.

post it simply here, maybe other peoples will help you too then ;)
 
Hi Vogor,
is possible see last revision of you schematics?( for this problem and for redesign new ritch FB. (for unipolar supply))
regards
Hi AP2, The scheme will be a bit later if I have cleaned short that T2, the making impulse of start and has connected Vb the driver to +Vc through the resistor 200K.
This is the output stage of my old project (2003).
component values are adjusted to obtain a good reproduction even at low audio frequency (40Hz) at power, and less noise as possible.
also the resolution at high frequencies sound is excellent.
nothing special, with this driver (IR2110 I used). I think they are all similar. Regards
In your scheme signals on Hin and Lin the driver go on another (on the contrary) and there are resistors 220R how it works? You had problems with start/deenergizing in this scheme (impulses on an exit did not appear)? For what FB-2? What principle of work "Potenz/startup Delay", mosfet's gate should incorporate with-Vc through a time interval for driver start? If to increase the resistor 1,5K that will occur with DT will grow or will go down?
 
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It is not needed to deenergize the driver, it is needed to shutdown it, using SD pin of IR2110.
Do not broke too much of mosfets, otherwise experiments will be too expensive ;)
post it simply here, maybe other peoples will help you too then ;)
For "smooth" deenergizing of the amplifier it is strong necessary to switch off at first the driver and then other power supply, it is possible to see an example of simple realisation of the given decision?
 
For "smooth" deenergizing of the amplifier it is strong necessary to switch off at first the driver and then other power supply, it is possible to see an example of simple realisation of the given decision?

It is here :) After switching the amp ON, two resistors (100K and 4.7K) will produce about 0.8V at T3 base. T3 will open and remove the SD signal from driver. Amp will start. When switching the amp OFF, the -V voltage will slowly fall down, and at about 15-20V transistor T3 will close again and produce the SD signal. So the driver will be disabled, when the power supply will be 'deenergized' to about 15-20V... Maybe it will be needed to vary the 100K resistor between 150-200K to get the desired effect :)
 

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It is here :) After switching the amp ON, two resistors (100K and 4.7K) will produce about 0.8V at T3 base. T3 will open and remove the SD signal from driver. Amp will start. When switching the amp OFF, the -V voltage will slowly fall down, and at about 15-20V transistor T3 will close again and produce the SD signal. So the driver will be disabled, when the power supply will be 'deenergized' to about 15-20V... Maybe it will be needed to vary the 100K resistor between 150-200K to get the desired effect :)
Thanks for a good and simple example, I will try. But it would be desirable to understand all the same because of what there is an impulse, after all a driver PSU falls down almost as smoothly as well as the main voltage?
 
ok, ... old schematic has a modulator (not self Oscillator)
have out relay. Delay is a quick startup time for balanced modulator, after this, enable drive MOSFET.(at switch-off,use this for off driver)
220R attenuated glish (not influence the wave becouse input-2110 is high impedance).(this res is in relation with pcb, gndPlane etc..)
1.5 K and BJT :)is critical stage (many do not know) this is liable (if the previous stage is very good, fast rise-fail time) of good sound reproduction at high frequencies (usually many class D seems to mp3).
this resistors can adjust the sides of the PWM.
it is clear that if you put on a 10K open-collector at 300kHz rise-time it will be very slow.
with 100R is very fast (but power dissipation increments) this is normal.
1.5 K with bcx53 I got very good resolution on sound.
Obviously, the modulator is very good.:)
 
Thanks for a good and simple example, I will try. But it would be desirable to understand all the same because of what there is an impulse, after all a driver PSU falls down almost as smoothly as well as the main voltage?

The impulse is generated, because opamp is switched off before driver and mosfets are 'deenergized'... for example at +/-10 volts the opamp wil get too low voltage through 1.8K resistors and will not work anymore, although there is still a lot of energy at output mosfets. Oscillation stops and since the output can be only in two states (-V or +V), the strong impulse is generated.
 
ok, ... old schematic has a modulator (not self Oscillator)
have out relay. Delay is a quick startup time for balanced modulator, after this, enable drive MOSFET.(at switch-off,use this for off driver)
220R attenuated glish (not influence the wave becouse input-2110 is high impedance).(this res is in relation with pcb, gndPlane etc..)
1.5 K and BJT :)is critical stage (many do not know) this is liable (if the previous stage is very good, fast rise-fail time) of good sound reproduction at high frequencies (usually many class D seems to mp3).
this resistors can adjust the sides of the PWM.
it is clear that if you put on a 10K open-collector at 300kHz rise-time it will be very slow.
with 100R is very fast (but power dissipation increments) this is normal.
1.5 K with bcx53 I got very good resolution on sound.
Obviously, the modulator is very good.:)
It all means that with increase in this resistor increases DT?
 
Not increase or decrease DT(deadTime).
ADJ this resistor IN REALATION at DT on mosfet-gate.
IR2110 have antioverlapped, UVLO, and DeadTime on chip + external with R-Diode on gate.
(depends on the gate capacitance).
My english is the problem. not amplifier.:):)
 
The impulse is generated, because opamp is switched off before driver and mosfets are 'deenergized'... for example at +/-10 volts the opamp wil get too low voltage through 1.8K resistors and will not work anymore, although there is still a lot of energy at output mosfets. Oscillation stops and since the output can be only in two states (-V or +V), the strong impulse is generated.
Ok, I in an amplifier PSU have two "banks" - 47000mFx80V, ballast resistors now for opamp - 2x2,7K/2W and for a PSU of the driver and logic the separate stabilizer 7812+200mFx16V, will try reduce condenser capacity (200mF) can driver will be closed faster and will not be output impuls.
 
Ok, I in an amplifier PSU have two "banks" - 47000mFx80V, ballast resistors now for opamp - 2x2,7K/2W and for a PSU of the driver and logic the separate stabilizer 7812+200mFx16V, will try reduce condenser capacity (200mF) can driver will be closed faster and will not be output impuls.

You can try it, but I think this will not help, because the driver will stop work LATER than opamp anyway.
Also, do not forget about the error with caps (see my previous post).
 
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