I have an outdoor lighting transformer (operating at the usual
12VAC) that I want to add a strip of LED lights in a new run. The transformer has two legs, each supplying up to
300W of load at either
15V (4 contacts per leg). The strip light controller takes
12VDC at up to
12A, but I will only be connecting a single strip that consumes
I know that to convert the power source to DC I will need a bridge rectifier and then something to smooth the ripple. I'm not sure what the tolerance of the RGB controller is (guessing
0.5V, I might be able to confirm that tonight). Based on my research over the past few days it sounds like the BR will boost the output DC voltage (due to RMS vs peak) so I will need some resistors or diodes to drop the voltage back down to
12VDC. As this converter will be living outside my intent is to keep things compact enough that I can weather proof it without much effort (either small enclosure, or epoxy and heat-shrink tubing).
I have a reasonable understanding of how the circuit design should look, but where I am not confident is on the specs of the components. For the BR, is at least
6A If reasonable or should I pad that with at least
12A If (especially if I want to add another
6A run on the end of this run)? A
20A If BR is only about
$2.00 so no big deal on price. All BR's in this range seem to support very large peak reverse voltages (usually
600V+), are there any minimum specs I should take note of?
For capacitance, I am using the
C = I / (Vdrop * Ifreq * 2) formula. In my case that is
C = 6 / (0.5 * 60 * 2) = 100 mF which seems very high, but perhaps necessary for this type of circuit (with load this high)? Is it more reasonable to use multiple caps instead? I know that I will need
25V caps to handle the 12VDC coming out of the BR. I can pick up a cap with these specs for about
$6.00 so again, no big deal price wise.
Are there any other considerations that I should be aware of? I am certainly not a professional electrician, but I understand the general concepts. Building the circuit and soldering the parts together is no problem for me, it's just some of the finer details that I would like some feedback on to make sure I'm on the right track.
Finally, what I am attempting to recreate is a product available on Amazon but not available in Canada (where I live). Based on it's size and shape I'm almost certain that it is composed of a BR and (at least one) capacitor. Possibly some other parts to regulate the voltage?
Here is a (very basic) circuit diagram that I am expecting to build. I just put
1kOhm for the controller as a reasonable amount of load resistance for the LED strip (not sure what the actual value is, but maybe I can figure that out later).
Thanks for any help.