40V dual power supply

john July 30, 2009 78 Comments

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.

40v-dual-power-supply

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.
Comments
  • Shajeel
    March 29, 2013

    i want to make -30V t0 + 30V dual regulator power supply so plzz give me some circuit of it if u have…Regards

  • Shajeel
    March 29, 2013

    is it posible to make -40V with out using negative regulator ic?

  • September 3, 2012

    hi seetha raman i want to make a INPUT 16 to 60V AC/DC. OUTPUT +5V-5V, 20 mile AMP power supply of plz send me the circuit diagram to my Email address.

  • keith
    March 2, 2011

    hi seetharaman, so if I want to change this power supply to a variable one, potentiometers at the output are not enough ?

  • admin
    February 28, 2011

    For using this power supply to power two 150W amp modules slight modifications are required

    Transformer must be raised to 350 VA.
    Current rating of the bridge must be raised to 12 or 15 A.
    Fuses must be changed to 12A.

  • segzy
    November 24, 2010

    u’re jst xcelent.u tak d pain 2find soln 2peopls prblems.u’re a ist clas engr and mentor. thanks and kep it up

  • Seetharaman
    September 29, 2010

    Hi Mounica you require a maximum current limitting of 30% of the rated battery capacity that is 30amps (for flat battery of less than 11volts terminal voltage)and normal charging current of 1/10 of the rating that is 10 amps at 12volt.

  • mounica
    September 29, 2010

    can you give me that external charging circuit

  • Seetharaman
    September 29, 2010

    Hi Mounica you can use 100AHbattery for operating the UPS but it is not rated to charge it, hence you have use an external charger.
    Hi Adnan When you bridge two identical amplifiers into the speaker of same impedance, then it will give 4 times the rated power. i will email you the details

  • mounica
    September 29, 2010

    Hello seethraman i have APC ES-500 UPS it has 12v 7Ah battery
    can i use 12v 100Ah battery instead of 7Ah
    this 100Ah battery will spoil the ups?

  • Adnan
    September 28, 2010

    what changing will i have to do for increase or decrease the voltage?

  • Seetharaman
    September 28, 2010

    Hi Adnan Use a power transistor like 2N3055 with 12 volt zener in the base collector circuit and connect collector emitter to filter capacitor. the following site will give you the idea and design of shunt regulator
    http://www.tpub.com/content/neets/14179/css/14179_212.htm

  • Adnan
    September 28, 2010

    if i want to make this transformer less supply for TDA1554 which gives 12v @5A what will i have to do?

    http://home.scarlet.be/johnstaybank/psu_transformerless.htm

  • Adnan
    September 28, 2010

    how can i connect or use a shunt regulator?

  • Seetharaman
    September 27, 2010

    Hi Adnan my PC is through I will send you by wednesday positively.
    Regarding these power amplifiers they are not Class A type that is conuming constant current, but they are class B type hence as per volume their current requirement vary from few mA to few thousands of mA. hence the voltage will vary from 12 volt to almost the AC supply voltage which is likely to kill all the components hence you have to use a shunt regulator to take care for the full current capability.

  • Adnan
    September 26, 2010

    your PC is Ok now so kindly mail me the 60v dual supply modified circuit

  • Adnan
    September 26, 2010

    But Mr Seetharaman if i use 220uF capacitor instead of 120uf capacitor as you told me then according to your calculation it will have to give approximate 9A
    (0.47 X 9) / 0.02=211.5uf apprx 220uf????

  • Adnan
    September 26, 2010

    its mean i can use this power supply 12v @ 5A for TDA1554?

  • Adnan
    September 26, 2010

    what changing will i have to do for increase the voltage?

  • Seetharaman
    September 26, 2010

    Hi Adnan the max current can be 5 Amps at 12 volts. if you want to increase the output voltage the current will fall down. If you short the output the maximum current can be 5amps only.

  • Adnan
    September 26, 2010

    if use 220uf @ 400v instead of 12ouf what will be the output current @ 12volts?
    and if we want to increase the voltage what changing will required???

  • Seetharaman
    September 25, 2010

    Hi Adnan with 0.47uF you will get 20mA, for 5Amps you require (0.47 X 5) / 0.02 you require around 120uF 400 volt capacitor for continuous rating. check for the availability and price. this may be very expensive comparing to switched mode power supplies which are quite efficient and pretty small in size. 12 volt 5amp Halogen bulb power supplies are available for as low as INR150/- very small 2″ X 1″ X 1″ few grams in weight. efficiency >90%

  • Adnan
    September 25, 2010

    hi seetharaman plz see the following link its contain a transformer less powersupply and it is written on the instructions that if we increase the value of capacitor we get more current so tell me how can i get 5A current at 12v what value will be taken for 5A current please see im waiting

    http://home.scarlet.be/johnstaybank/psu_transformerless.htm

  • Adnan
    September 24, 2010

    Im waiting for the power supply circuit

  • Adnan
    September 23, 2010

    plz ,mail the revised circuit?

  • Adnan
    September 23, 2010

    plz ,ail the revised circuit?

  • Seetharaman
    September 19, 2010

    Hi Adnan my PC is back. I am just on the job by tuesday i will mail the revised circuit

  • Adnan
    September 18, 2010

    is ur PC is ok now Mr.Seetharaman

  • seetharaman
    September 10, 2010

    Hi Adnan if by chance if the output is shorted or load takes higher current as per the capability of the trransformer then the rectifier will get destroyed. hence it is preferable to use higher rating bridge rectifier.

  • Adnan
    September 10, 2010

    if we have 4Amp transformer then we have to use more than 4Amp bridge like 6amp why we use high ampere rating bridge?and what will happened if we use low ampere bridge when transformer current is high??

  • seetharaman
    September 9, 2010

    Please wait my PC will be ready this sunday you will positively get it on tuesday.

  • Adnan
    September 8, 2010

    plz send the modifies circuit with thyristor and zener u’ve told me last week?

  • Adnan
    September 2, 2010

    if the transistor quantity is decreased it will better for me because i will easily afford it thankyou

  • Adnan
    September 2, 2010

    i asked today in the electronics market but the TIP122 & TIP127 is not available in the market

  • seetharaman
    September 2, 2010

    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.

  • Adnan
    September 1, 2010

    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??????

  • Adnan
    September 1, 2010

    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?

  • adnan
    August 31, 2010

    oh its ok Mr Seetha raman

  • seetharaman
    August 31, 2010

    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.

  • adnan
    August 31, 2010

    please mail me the circuit Mr Seetha raman

  • adnan
    August 29, 2010

    plz mail me the power supply circuit

  • adnan
    August 24, 2010

    no no Mr seetharaman its ok i’ll wait for 3 or 4 days thankyou for all the help

  • seetharaman
    August 24, 2010

    Hi Adnan i will mail it to you in 3 to 4 days time sorry for the delay.

  • adnan
    August 23, 2010

    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

  • seetharaman
    August 23, 2010

    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

  • adnan
    August 6, 2010

    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

  • Nathan
    August 5, 2010

    IS THIS A SWITCH MODE POWER SUPPLY.

  • adnan
    August 4, 2010

    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

  • adnan
    August 4, 2010

    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

  • seetharaman
    August 4, 2010

    Use a 7812 3pin voltage regulator. add 1k resistance to the input of the regulator IC

  • joel
    August 4, 2010

    Hi seetharaman

    i want to reduce this 40v to 12v to connect to pre-amplifier

    how can we reduce tell me please

  • adnan
    August 4, 2010

    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

  • adnan
    August 3, 2010

    plz send me the circuit diagram with the series pass transistor

  • seetharaman
    August 2, 2010

    Hi Adnan you can provide series pass transistors with its base being controlled by variable reference.

  • adnan
    August 2, 2010

    can i make the above power supply into a variable power supply for both channel

  • seetharaman
    August 2, 2010

    Hi Adnan with higher capacity power supply(current) you can always draw lesser current. but not the other way round.

  • adnan
    August 1, 2010

    i cant understand what do you mean by $1000 and $600

  • seetharaman
    August 1, 2010

    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.

  • seetharaman
    August 1, 2010

    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.

  • adnan
    July 31, 2010

    if i connect two potentiometer in parallel at +40-0 and -40-0 will it become a variable power supply?

  • adnan
    July 31, 2010

    if i use 35-0-35 @ 4amp transformer instead of 30-0-30 what will be the output?

  • adnan
    July 18, 2010

    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??

  • seetharaman
    July 18, 2010
  • adnan
    July 18, 2010

    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???

  • adnan
    July 18, 2010

    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???

  • seetharaman
    July 18, 2010

    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.

  • adnan
    July 17, 2010

    if i give more than 25v to a 220uf 25 volts capacitor what will happen?what will the output or the capacitor will destroy??

  • adnan
    July 16, 2010

    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????

  • seetharaman
    July 14, 2010

    Yes you can use if you have space.

  • adnan
    July 12, 2010

    if i need 220uf 50v capacitor but i have a capacitor of 220uf 400v can i use 220uf 400v capacitor instead of 220uf 50v???

  • seetharaman
    July 12, 2010

    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.

  • adnan
    July 11, 2010

    200va means how much amperes of transformer tell me?

  • adnan
    July 11, 2010

    if we increase the capacitor voltage rating to 200v 4700uf what will be the effect on output voltage

  • Jed
    August 3, 2009

    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

    • admin
      August 4, 2009

      yes, the power supply ratings must be doubled.

  • Jared Cook
    August 3, 2009

    Would this be suitable for a stereo amp based on two of the 150W amplifiers or would two separate power supplies be required? Cheers

    • admin
      August 4, 2009

      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.

Leave a Reply

Your email address will not be published. Required fields are marked *