or read some real info about battery charging, like my earlier link or
Charging Nickel-Metal-Hydride Batteries ? Battery University
as I said you can "make do" with poor performance by real world standards as a hobbyist - but I think it is uesful part of this forum that there is often someone to show the limits, costs of "too simple" hobby techniques
Charging Nickel-Metal-Hydride Batteries ? Battery University
as I said you can "make do" with poor performance by real world standards as a hobbyist - but I think it is uesful part of this forum that there is often someone to show the limits, costs of "too simple" hobby techniques
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Tangent recommends using Linear-Regulated power supplies for high performance audio, and specifically mentions the Elpac WM series.
Does anyone know if there is a European counterpart to this supply, or can anyone recommend an alternative linear-regulated 24V DC wall plug, available in europe?
Does anyone know if there is a European counterpart to this supply, or can anyone recommend an alternative linear-regulated 24V DC wall plug, available in europe?
Well, I read the whole of the "Battery University" section on NiMh charging and discovered that 0.05C is rated as suitable for trickle (indefinite) charging.
Taking a typical 8.4V rechargeable's capacity as 270mA, the resistor values in both agdr's circuit and those in the O2's circuit result in charge rates of 0.75C, falling to <0.05C, producing something approaching 100% charge in ~15 hours.
These factors together belie your claim that overnight charging and 100s of cycles really need a smarter circuit.
I also did a google search for "O2 headphone amp battery problems". I found nothing significant, and there is a thread here on the O2 with over 3500 posts, stretching back over 2 years, and most of which I have read without noticing a theme of persistent battery problems.
the recomendation varies, the lower estimate I have seen is < 1/40 C - thats not overnight
even c/20 isn't overnight
c/10 is abusing the battery specs -relying on fallible human behavior to "time terminate" the charge - but may in practice "work" well enough for a hobby project
and as I keep saying - hobbyists can get away with less than good practice on this - many will get bored, move on to something else before they run up even 50 recharge cycles on their 1st cheap homebrew amp
at the very least I made you look - can't as quickly drum in 30 years of engineering design experience telling me to be way on the safe side of limiting specs
even c/20 isn't overnight
c/10 is abusing the battery specs -relying on fallible human behavior to "time terminate" the charge - but may in practice "work" well enough for a hobby project
and as I keep saying - hobbyists can get away with less than good practice on this - many will get bored, move on to something else before they run up even 50 recharge cycles on their 1st cheap homebrew amp
at the very least I made you look - can't as quickly drum in 30 years of engineering design experience telling me to be way on the safe side of limiting specs
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just putting out real design info, in this case for apparent beginners to electronics building the "CMOY" and I'm pointing out sub optimal battery recharging
since we don't know what NiMH battery will be used we should use the most conservative manufacturers trickle charge current recommendation if using that technique
since we don't know what NiMH battery will be used we should use the most conservative manufacturers trickle charge current recommendation if using that technique
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