tornado 4000.1

[Sergei83]

Good evening. Faced with the problem of tornado 4000.1. The amplifier consists of 4 half bridges. Individually, each operates at a frequency of 100 kHz. 3 out of 4 are also launched, but not one does not work with one half bridge. If you include a pair of output constant -1.8V. if you turn on all 4 the output HO transistors explode in two half-bridges and LO in one. Already went through everything and replaced everything, but alas

 

[Perry Babin]

Do you have any experience with the 21844 amps?

 

[Sergei83]

I understand how they work

 

[Perry Babin]

They are very easy to damage when installing. Do you think you may have heated them up too much when installing them?

If one fails, it often causes the others to fail.

 

[Sergei83]

oscillograms of work. Measured about ten minutes ago. Two half bridges, but do not work together

 

[Sergei83]

вот схема усилителя, только без драйвера
View attachment TS_4000_1.pdf

 

[Sergei83]

here is the amplifier circuit, only without driver

 

[Perry Babin]

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[Sergei83]

What else can I attach to the message? Honestly, already tried everything
changed the gate resistance, feedback circuit, also changed the throttle in some places
swapped choke from different half bridges

 

[Perry Babin]

I would install one 21844 and try to get it working. Working with a low rail as was suggested in the first thread you posted in will help reduce the possibility of doing damage to new parts.

 

[Sergei83]

ndividually, they both work. Two 21844 are now installed, and they do not interfere with each other if you include one at a time. There is a sound, at the output - 0.09 V
I just can not understand why they do not run together, they are on one level shifter. just the other two in pair work

output transistors explode only if you start a "bad" half-bridge with another level shifter

 

[Sergei83]

half bridges
1 2

3 4
works 1+2,2+4,1+2+4
does not work 1+3
transistors explode 3+2, 3+4
1+2+3+4 transistors explode LO 2 and LO+HO 4
1 + 3 common shifter
2 + 4 common shifter

 

[Perry Babin]

If you go to a low voltage supply, fewer parts will fail during troubleshooting.

Sometimes, intermittently shorted inductors can cause problems like this.

Did the replacement parts come from a reputable distributor?

 

[Sergei83]

inductance measured by the device, problems like no.
Pro spare parts did not understand
What voltage can I switch to?

 

[Perry Babin]

I don't understand the question. Did you read the previous thread you posted in about using a low voltage supply made by adding extra windings?