The 2.5 VAC (Volts-AC) outputs of our RDX-200 can be combined in parallel if you need more current capability as long as they are properly phased. If you were to accidentally hook up the two sets of 2.5 volt windings incorrectly, the phases (sinusoid wave form) would be fighting each other and end up toasting the transformer.

You can determine if the two sets of outputs are properly phased with a simple AC volt meter (RMS).

Locate the two sets of 2.5 VAC secondary wires (Orange-Green-Orange and Blue-Blue/White-Blue).

Label the two orange wires from the first 2.5 VAC secondary winding as wires "A" and "B". It doesn't matter which is which but once assigned a label it will matter. Label the two blue wires from the second 2.5 VAC secondary winding "C" and "D". You can label them temporarily with something like masking tape.

Make sure the ends of all other wires are insulated so they don't short out.

Connect wire "A" on the first winding to wire "C" on the other winding set. Do not connect "B" and "D".

Put the voltmeter across wires "B" and "D".

One note of caution. When powering up the transformer to check the phasing, power it up and take your readings quickly so that if something IS miswired, you aren't as apt to toast the transformer.

When you power it up, you will see either approximately 0 volts or 5 VAC. Taking this reading should not harm the transformer as long as you only connected one wire from each of the 2.5 VAC windings as described above.

Power it down.

If you saw 0 VAC, then you can leave wires "A" and "C" connected. Connect the other two wires ("B" and "D") together. Now when you power up the transformer and read across the two sets of connected wires (A/C and B/D), you should read 2.5 VAC. Your 2.5 VAC outputs are now properly paired up with the same phasing. You may also tie the green and blue-white wires together for a common center tap if a center-tap connection is needed.

If you saw 5 VAC, then disconnect wires "A" and "C". Now connect wire "A" to wire "D". You can also connect wires "B" to wire "C". Now when you power it up and read across the two sets of connected wires (A/D and B/C), you should read 2.5 VAC. Your 2.5 VAC outputs are now properly paired up with the same phasing. You may also tie the green and blue-white wires together for a common center tap if a center-tap connection is needed.

Note: When using these windings in parallel, you should connect both sets together at a common point and the load distributed from that common point.

If you have any additional questions, please Contact Us at Radio Daze.