Perhaps another small typo on the Slides?
Slide 3, last sentence: should it be "For Q2 and Q4..." rather than "For Q1 and Q4..."?
Slide 3, last sentence: should it be "For Q2 and Q4..." rather than "For Q1 and Q4..."?
@Bonsai
Is there a minimum current draw requirement for the micro ripple eater to function properly? Obviously Class A/AB amps (in example the KX2) should be adequate but how about amplifiers that have less than 100mA quiescent (i.e. mostly Class AB)? There is of course a paradox in this question in that one would ask why? Just use some 10mF caps in a basic full wave rectified center tapped supply and be done! I’m well aware of that, but I like asking the theoretical to fund my knowledge.
Is there a mathematical calculation to verify if the pass transistors are being utilized “effectively under load” for lack of a better word?
I am reading Rod Elliot’s treatise on this subject for better reference.
Your MRE appears to be a Darlington design.
Best,
Anand.
Is there a minimum current draw requirement for the micro ripple eater to function properly? Obviously Class A/AB amps (in example the KX2) should be adequate but how about amplifiers that have less than 100mA quiescent (i.e. mostly Class AB)? There is of course a paradox in this question in that one would ask why? Just use some 10mF caps in a basic full wave rectified center tapped supply and be done! I’m well aware of that, but I like asking the theoretical to fund my knowledge.
Is there a mathematical calculation to verify if the pass transistors are being utilized “effectively under load” for lack of a better word?
I am reading Rod Elliot’s treatise on this subject for better reference.
Your MRE appears to be a Darlington design.
Best,
Anand.
Hello Anand. Yes, the MRE is a Darlington design. I did not specify a minimum load, but it will work fine with anything more than c. 50mA which is what I tested it with on the low side.
The RC filter corner frequency on the MRE is set to well below 1Hz. So, any frequencies substantially above this ie typical audio signals, will be filtered out and will manifest as a change in DC voltage at its output. Another way to look at this is to imagine the MRE exchanges or converts AC ripple on the input to a shift in DC output (minus the ripple).
You could do all sorts of calculations to work out the output impedance, step load response etc, but a simulation gives good working results so that’s what I did. This is a well tried and tested technique that’s been around for decades.
You will get lower voltage drops across a Sziklai arrangement but I’d only go down that route it I was desparate for an extra volt or do of amplifier output swing.
cheers
A
(the Rod Elliot design looks interesting - thanks for the link).
The RC filter corner frequency on the MRE is set to well below 1Hz. So, any frequencies substantially above this ie typical audio signals, will be filtered out and will manifest as a change in DC voltage at its output. Another way to look at this is to imagine the MRE exchanges or converts AC ripple on the input to a shift in DC output (minus the ripple).
You could do all sorts of calculations to work out the output impedance, step load response etc, but a simulation gives good working results so that’s what I did. This is a well tried and tested technique that’s been around for decades.
You will get lower voltage drops across a Sziklai arrangement but I’d only go down that route it I was desparate for an extra volt or do of amplifier output swing.
cheers
A
(the Rod Elliot design looks interesting - thanks for the link).
