40V dual power supply
Description.
This 40V dual power supply circuit was designed in response to a request made by Michael from Philippines. His application is to power the 150 Watt amplifier circuit published here. I think this power supply design is adequate for the purpose. The transformer T1 steps down the mains voltage, bridge D1 performs the rectification, C1 and C2 does the job of filtering.C3 and C4 are decoupling capacitors.
Circuit diagram with Parts list.
Notes.
- The T1 must be a 230V primary, 30-0-30V secondary, 200VA transformer.
- All capacitors must be rated at least 63V.
- C3 and C4 are polyester capacitors.
- If 8A bridge is not available, make one using diodes like P600A.



Would this be suitable for a stereo amp based on two of the 150W amplifiers or would two separate power supplies be required? Cheers
In order for this supply to be used for two 150W amps – left and right – would it be necessary to increase the VA of the transformer – if so – by how much? Cheers
yes, the power supply ratings must be doubled.
two seperate power supply will reduce noise, but it is very costly.
Here a single power supply with double ratings is enough for stereo mode.
if we increase the capacitor voltage rating to 200v 4700uf what will be the effect on output voltage
200va means how much amperes of transformer tell me?
By increasing the voltage of the capacitor will not have any effect on the output power.
200va / 60volt is 3.333Amps.
30-0-30volt transformer, both the 30 volt winding should be capable of giving >3amps current.
if i need 220uf 50v capacitor but i have a capacitor of 220uf 400v can i use 220uf 400v capacitor instead of 220uf 50v???
Yes you can use if you have space.
if i have a power supply of 30 volts 12 amp.Is this is possible to get 30 volts 6amperes from the 30volts 12amps power supply????
if i give more than 25v to a 220uf 25 volts capacitor what will happen?what will the output or the capacitor will destroy??
Hi ADnan the capacitor will get heated up and explode. For a 25 volt capacitor 20volt will be safe limit. in some capacitor they would have mentione the voltage at 85deg C. These capacitors can be used upto the rated voltage. if temp is not mentioned in a capacitor, it is to be taken as 25deg C and derate it and use it at one third the voltage indicated. since inside the equipment the ambient may raise to 75 deg C.
p600 diodes can make a 8 amp bridge
tell me the equivalent diodes for 6 amp bridge, 4 amp bridge and 2 amp bridge diodes name???
p600A diodes can make a 8 amp bridge
tell me the equivalent diodes for 6 amp bridge, 4 amp bridge and 2 amp bridge diodes name???
Hi Adnan please refer to IR datasheets
http://www.alldatasheet.com/datasheet-pdf/pdf/83183/IRF/1N3208.html
if i have a power supply of 30 volts 12 amp.Is this is possible to get 30 volts 6amperes from the 30volts 12amps power supply??
if i use 35-0-35 @ 4amp transformer instead of 30-0-30 what will be the output?
if i connect two potentiometer in parallel at +40-0 and -40-0 will it become a variable power supply?
Hi Adnan why not for very low currents. for higher current add few series pass transistors.
Any transformer you can use, out put will be root 2 times the AC input.
Hi Adnan you have US$1000 in your account hence you can draw easily US$600 from your account.
You can draw 6 amps comfortably.
i cant understand what do you mean by $1000 and $600
Hi Adnan with higher capacity power supply(current) you can always draw lesser current. but not the other way round.
can i make the above power supply into a variable power supply for both channel
Hi Adnan you can provide series pass transistors with its base being controlled by variable reference.
plz send me the circuit diagram with the series pass transistor
hi i want to make a dual variable power supply of +5,-5 to +60,-60 volts @ 4A plz send me the circuit diagram to my Email
adnan_khan_yzai@hotmail.com
Hi seetharaman
i want to reduce this 40v to 12v to connect to pre-amplifier
how can we reduce tell me please
Use a 7812 3pin voltage regulator. add 1k resistance to the input of the regulator IC
hi seetha raman i want to make a dual variable power supply of +5,-5 to +60,-60 volts @ 4A plz send me the circuit diagram to my Email
adnan_khan_yzai@hotmail.com
hi seetharaman i want to make a dual variable power supply of +5,-5 to +60,-60 volts @ 4A plz send me the circuit diagram to my Email
adnan_khan_yzai@hotmail.com
IS THIS A SWITCH MODE POWER SUPPLY.
i want to make a dual variable power supply of +5,-5 to +60,-60 volts @ 4A plz send me the circuit diagram to my Email
adnan_khan_yzai@hotmail.com
Hi Nathan this is just the simplest unregulated plus minus power supply. Please go through the earlier article on switched mode power supply for the basic idea http://www.circuitstoday.com/switching-regulator-using-lm1758-a
hi seetha raman i want to make a dual variable power supply of +5,-5 to +60,-60 volts @ 4A plz send me the circuit diagram to my Email address
adnan_khan_yzai@hotmail.com
Hi Adnan i will mail it to you in 3 to 4 days time sorry for the delay.
no no Mr seetharaman its ok i’ll wait for 3 or 4 days thankyou for all the help
plz mail me the power supply circuit
please mail me the circuit Mr Seetha raman
Hi Adnan please bear with me for few more days my desk top is down i am using my mini for just emails no graphics possible.
oh its ok Mr Seetha raman
Thank you very much Mr seetha raman for the circuit you solve a big problem for me now after implementing this supply i will be able to power many of amplifier circuit and other circuit thanks again
i understand all the working of this supply but tell me that why we use too much transistors?what happened if we decrease the quantity of transistor?n tell me if there any replacement exist to decrease the quantity of transistors?
if i want to use 50-0-50v @ 12amp transformer in that power supply you’ve mailed me then what changing will be made except of bridge rectifier or will the circuit remain same??????
With 12 amp transformer your short circuit dissipation of the trasistors are 1200 watts 600 at + and 600 at -. That is you require around 20 transistors in parellel on heat sink.
to reduce the number of transistors a thyristor to be added with suitable zener and transistor, you can make a very compact high current variable power pack. i will send the circuit by next week.
i asked today in the electronics market but the TIP122 & TIP127 is not available in the market
if the transistor quantity is decreased it will better for me because i will easily afford it thankyou