Negative to Positive Voltage Converter ?

[vikasveshan]

Hi All ,

Please Suggest me both Integrated and discrete solution to convert -15V to 15V with output power requirement of 0.5W to 1W.

Thanks & Regards !!

V V

 

[raksha singh]

please specify it would be ac or dc voltage ....
there are so many topology used for converting you can use according to your specification.....also specify current...

 

[vikasveshan]

Its a DC Voltage , required Output Current is near about 60mA .

Please explain me the various topologies used for Conversions .

Regards !!
V V

 

[raksha singh]

SMPS Switching Power Supply Topologies: Comparison and Selection

i think this link will help you .....here there are so many topology according to parameters......you can go for which is suitable for you ...

 

[vikasveshan]

Sorry , didnt find any suitable topology for my requirement .
Anyways thanks !!

Regards !!
V V

 

[vimalkhanna]

Are the terminals floating for the neg. supply .Just change the ground lead and use it ,
Use an STMicro VIPer10 or er22 to switch a T10 toroid and generate a 15VDC @100mA ..
I you want ckt attachment ,I can send you the ckt and PCB design .

 

[ee_pcb]

Hi all,

You can do this with a simple op-amp circuit and a pass BJT (for the power). Op-amp: Vcc = Vout+Vop-amp drop. Vcc- or Vee = 0 volts (ground). Set your Av to >100 <1000. Av = -(Rf/Rin). Your negative Vin (-Vin) will be applied to the negative input of the op-amp via the Rin resistor. the non-inv. pin is tied to ground. Put a load resistor on the output to ground (say, 33K or so). Tie the op-amp output to the base of a NPN BJT. Use a BJT with a beta of 100 or better. Tie the Collector of BJT to Vcc. Attach the emitter to ground via a "developing" resistor, say a 4.7K or so to set your Iec for saturation. Attach your output lead to the top of the emitter resistor. When you have a negative input voltage, you will have a Vcc-Vec output voltage. Perhaps I will attach a shematic to help in a later post.

 

[ee_pcb]

I have since come up with a better idea. Use an optocoupler to detect the negative voltage (say a 4N25). Tie the anode of the diode to ground (0 V) and the cathode to your negative voltage (using an appropriate series resistor). Use your emitter or collectore on the opto-transistor as you see fit, this will be your output. Use that output to drive a pass transistor. Cheers