MC34063 DC-DC BUCK CONVERTER

[TuralH]

Hello everyone, I need to assemble a circuit to control a DC motor, my 60V battery needs to be reduced to 12V, I have an mc34063 in my hands but its maximum voltage is 40V VCC, I assembled a circuit in LTSPICE with an external pmos but the circuit does not work in the simulation. that is, I supply 60 volts separately to pmos and 12 volts to IC separately, maybe someone will advise assembling the circuit differently, I need to get 12V 3A at the output to control DC motor

 

[KlausST]

Hi,

my 60V battery needs to be reduced to 12V,

Your circuit shows you already have a 12V supply ..

I_sns seems not to be wired correctly.
1N4148 diodes are far too small .. they are SIGNAL diodes .. but you use them in a POWER path. SIGNAL and POWER are two different things.
The manufacturer provides a datasheet and most probalbly design notes. --> use them.

***

but the circuit does not work

This is far from being a useful error description..

We need to know
* What do you expect
* what does not work as expected

What did you do to investigate the problem on your own?
I mean: you have a simulation tool --> so use it.
You can - and should - measure each single node in your scheamtic.

Best strategy is to FIRST decide how a signal of a node should look like regarding voltages and timing. Use paper and pencil to sketch it down.
THEN use the scope function to verify it.

I have an idea what´s happening. But I don´t have your simulation files ... and if I had .. I´m not very experienced with circuit simulation software.

Please see it as your job ... to debug "at least something" ... and report us the details of your expectations and results.

Klaus

 

[stenzer]

Hi,

on first glance I would say your P-channel MOSFET is turned on the whole time, as its maximum gate voltage is 12 V. To turn it off the MOSFET VGS has to be 0 V. Further, here your VGS is larger than 20 V, which is usually the typically maximum voltage difference a MOSFET can handle.

Also your circuitry (approach) does not match your problem desciption.

BR

 

[TuralH]

Hi,


Your circuit shows you already have a 12V supply ..

I_sns seems not to be wired correctly.
1N4148 diodes are far too small .. they are SIGNAL diodes .. but you use them in a POWER path. SIGNAL and POWER are two different things.
The manufacturer provides a datasheet and most probalbly design notes. --> use them.

***

This is far from being a useful error description..

We need to know
* What do you expect
* what does not work as expected

What did you do to investigate the problem on your own?
I mean: you have a simulation tool --> so use it.
You can - and should - measure each single node in your scheamtic.

Best strategy is to FIRST decide how a signal of a node should look like regarding voltages and timing. Use paper and pencil to sketch it down.
THEN use the scope function to verify it.

I have an idea what´s happening. But I don´t have your simulation files ... and if I had .. I´m not very experienced with circuit simulation software.

Please see it as your job ... to debug "at least something" ... and report us the details of your expectations and results.

Klaus

yes, about the 12 volt power supply, I get it using another converter to power the IC, but there the maximum current consumption is 700 mA, and I want to reduce the second converter with mc34063 for a DC motoryes, regarding the 12 volt power supply, I get it using another converter to power the microcircuit, but there the maximum current consumption is 700 mA, and I want to reduce the second converter with mc34063 for the DC motor

 

[KlausST]

Hi,

why handstands ...
* building one 12V 700mA supply
* a second 12V 3A supply
* with unsuitable controller and thus the need for extra circuitry.

Are you sure this makes sense?

Why not one single 60V (Battery) down to 12V one. Using an IC that is designed to do this..

Klaus

 

[TuralH]

Hi,

why handstands ...
* building one 12V 700mA supply
* a second 12V 3A supply
* with unsuitable controller and thus the need for extra circuitry.

Are you sure this makes sense?

Why not one single 60V (Battery) down to 12V one. Using an IC that is designed to do this..

Klaus

I have xl7005 and MC34063 for supplying MC34063 i use xl7005 can buck from 80v to 12v but current rate is 700mA for dc motor control i used MC34063 where input is 60V i want to get 12v 3A but with external transistor