TL 494 converter design

[contactz]

tl494 schematic

need help on designing step-down converter using TL494.
Any1 have schematic diagram on a 15V-9V converter using TL494?

 

[IanP]

tl494

Goto:
http://www.datasheetcatalog.com/datasheets_pdf/T/L/4/9/TL494.shtml
and download MOTOROLA data sheet.
There you will find a schematic diagram of step-down converter based on TL494 and pnp external transistor. The only one thing you will have to do is to calculate 2 resistor values for 9V output..
Regards,
IanP

 

[contactz]

tl494 step down

May i know which resistor values am i suppose to calculate? and how to go abt doing it.

 

[IanP]

tl494 converter

At this moment you have a 5.1kΩ resistor connected between the output and (+) input of the error amplifier (pin 1). As the Vref=5V the output is 5V. If you need 9V output you will have to divide the voltage that goes to pin 1 in the ratio 9/5. To do this leave this 5.1kΩ resistor as it is and connect additional resistor between output 0V and pin 1. This resistor may consist of 3.6kΩ resistor and 1kΩ variable resistor, to adjust the correct value around 4.1kΩ.
If you need another output voltage use this formula:
Vo=Vref(1+R1/R2) where Vref=5V, R1 is already egsisting resistor 5.1kΩ and R2 is the new resistor between the (+) input of the error amplifier (pin1) and output 0V.
Regards,
IanP

 

[contactz]

tl494 design

ok. I'll try that. Thanks

 

[stephens_forest]

tl494 schematic circuit

I've found some topics on TL494,

you can download them, I think

they are useful.

https://focus.ti.com/docs/apps/catalog/resources/appnoteabstract.jhtml?abstractName=slva001d

https://focus.ti.com/docs/apps/catalog/resources/appnoteabstract.jhtml?abstractName=slva059a

https://focus.ti.com/docs/apps/catalog/resources/appnoteabstract.jhtml?abstractName=slva057

good luck

best regards

need help on designing step-down converter using TL494.
Any1 have schematic diagram on a 15V-9V converter using TL494?