Circuit Power Supply

Since receiving the 3-pin ICS market regulator, the issue of designing circuits accumulation ability has made under and under discussion. However, new ICS aforementioned types of circuits absolute actuality ability amusement born in laboratories at about 1 ampere units. In addition, skills are necessary stages, because the air received (5A or 10A) ICS are current voltage regulator expensive. This is why capital acumen for hobbyists usually choose an extracted solution. Abstraction ability of cascaded stages are absolutely not that bad. For this reason, we accept acclimated the breakaway device for ambit presented above.

This regulatory ambit consulting for microcomputer systems and applications added to die for beating aggressive accumulation ability and achievement air was admitted to the aforementioned time. IC 723 acclimated to this architecture largely been replaced by new 3-pin regulators. However, IC 723 is adjustable and its contents are great abstruse in some points. This is configured in the ambit of the achievement levels of voltage 2V to 7V. Naked ability is produced by a similar acceleration voltage through a voltage doubler circuit, afterlight it, and acclimation it with a 3-pin regulator IC.

* The circuit can be placed into the existing Variable DC Power Supply metal cabinet.
* Q1 and Q2 must be mounted on heatsinks. Usually, bolting them to the metal case (through insulating washers etc.) proved effective.
* The full ±15V output can be achieved only if the secondary winding of the supply Transformer used in the Variable DC Power Supply is rated at 48V minimum (center tapped).
* When using this circuit, please set the Current-limit control (P1) of the Variable DC Power Supply to any value comprised in the 50mA - 1A range but not higher.
* The second Op-amp (IC1B) contained in the LM358 chip was not used, but its input pins were tied to the negative supply and the output was left open.

DC Power Supply Dual-rail Variable Part list:

R1 = 4.7K-1/2W
R1 = 4.7K-1/2W
C1 = 100nF-63V
C2 = 220µF-25V
C3 = 220µF-25V
C4 = 100nF-63V
C5 = 100nF-63V
Q1 = BD437
Q2 = BD438
IC1 = LM358

A heavy duty 13.8V regulated power supply is a fine thing to have in the shack, but unless you acquire one secondhand, is an expensive little beastie to buy. This means building one should be considered, not only for the cost savings, but also because you can brag about it on air to your mates. Of course, careful consideration must be given to the properties of the completed supply, and after talking to a few of my friends who have built their own and fallen into all the traps, here are the printable ones : RF proof, easy to make, commonly available parts used, but above

The details published provide a transformer and rectifier structure capable of providing 8 amps DC continuously (and short current peaks up to 20 amps). This is sufficient to adequately power SSB transceivers with 100W PEP outputs, BUT WILL NOT power a transceiver providing a continuous carrier of greater than about 40 watts.e.g. AM, FM, continuous key down morse, single tone SSB testing etc. Demanding a continuous output of more than 8 amps will result in thetransformer secondary overheating, with a possible fire risk. The reason we can get away with a supply with an 8 amp continuous rating is simply that speech is very “peaky” data, and so SSB has the odd high power peak but a very low average power level (usually about 20 -30% of peak value). It is on this basis thattransformer and heatsink sizes are usually selected for domestic hi-fi equipment.

Source: http://www.users.on.net/%7Eendsodds/ps20.htm