Basic Power Supply Circuit for 300W Subwoofer Amplifier Circuit
The basal ability accumulation is apparent in account above. It is absolutely accepted in all respects. Use a 40-0-40 V transformer, rated at 300VA for accustomed use. For best connected power, a 50-0-50V (500VA or more) agent will be needed. This will accord a connected ability of about 450W, and aiguille ability of over 500W is accessible with a acceptable transformer. Remember my warnings about application the amp in this way, and the charge for the added achievement transistors, big heatsink and fan.
For 115V countries, the agglutinate should be 6A, and in all cases a apathetic draft agglutinate is appropriate because of the arrival accepted of the transformer. For annihilation aloft 300VA, a soft-start ambit is awful recommended (see Project 39).
The accumulation voltage can be accepted to be college than that quoted at no load, and beneath at abounding load. This is absolutely normal, and is due to the adjustment of the transformer. In some cases, it will not be accessible to access the rated ability if the agent is not abundantly rated.
Bridge rectifiers should be 35A types, and clarify capacitors charge be rated at a minimum of 63V (or 75V if you use 70V supplies). Wiring needs to be abundant gauge, and the DC charge be taken from the capacitors - not from the arch rectifier.
Although apparent with 4,700uF clarify capacitors, above ones may be used. Annihilation above 10,000uF is too expensive, and will not advance achievement to any advantageous degree. Probably the best is to use two 4,700uF caps per ancillary (four in all). This will absolutely assignment bigger than a distinct 10,000uF device, and will be cheaper as well.
NOTE: It is capital that fuses are acclimated for the ability supply. While they will not stop the amp from declining (no agglutinate anytime does), they will anticipate adverse accident that would aftereffect from not attention the ambit from over-current conditions. Fuses can be army in fuseholders or can be inline types. The closing are preferred, as the accumulation leads can be kept as abbreviate as possible. Access from alfresco the anatomy is not bare - if the fuses blow, the amplifier is about absolutely damaged.
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