I'm intrigued, especially where our rechargeable batteries are involved.
"Pulsed DC", "Half-wave-rectified DC", "Constant-Current DC", "Constant-Voltage DC" I understand.
What is meant by "Raw DC". How does it differ from "DC" ?
I'm intrigued, especially where our rechargeable batteries are involved.
Just DC that hasn't been smoothed with a capacitor - either half or fullwave rectified from (say) a mains transformer- lots of lovely ripple
Yes, 20th century constant current ('ish) which was the 'preferred' charge method at the time (yes, I know it's not constant ) - lots of nonsense about 'nicad memory' - based on some drivel from NASA satellite data - many people made mucho dollars on that platformMartin wrote: ↑10 Sep 2018, 11:57 What surprises me - and perhaps I've missed something - is that the 'transmitter' 9.6V rectifiers are identical (save having different resistances) to the 4.8V 'receiver' rectifiers. Both types are just half-wave rectifying the AC voltage coming from a 15V transformer wiring. So you could charge a transmitter battery from one of the receiver connectors and it would still charge up fully - just taking a bit longer because of the higher resistance.
? It's still half-wave, so 50Hz - 20mS - full wave would give you 100Hz 10mS AFAICS.In terms of the charging current, it's a pulse-charger. The pulses come every 20 milliseconds and last for rather less than 50% of the whole cycle (just how much less depends on how much higher the peak voltage of the unloaded AC is, compared to the voltage of the battery on charge). If I'm right about the same circuit and transformer winding being used for both receiver and transmitter batteries, then the transmitter batteries will be charged with shorter pulses, occupying a smaller fraction of the total time, than the receiver batteries.
You mean like this lot on my charging stationMike_K wrote: ↑11 Sep 2018, 11:17 But why not invest in a modern charger? They nearly all use PWM for current control, so you still get you pulsed charging, albeit at a higher frequency. You can still slow charge if you want or if in a hurry do a quick charge. Better still you can occasionally do a full discharge - charge cycle to see their true capacity which is a good indication if they're still up to the job. And they're not much more expensive to buy than building your own geriatric charger© (I think I should Copyright that name )
Yep, that all looks about rightMartin wrote: ↑10 Sep 2018, 22:07 Yes, still 20 ms pulse spacing, but the charge current only flows when the half-wave voltage exceeds the battery voltage. With a 4.8V battery on charge this will be perhaps 25% of the whole cycle time, but with a 9.6V battery on charge it will only be about 10% of the whole cycle time because only the topmost part of each peak is higher than the battery voltage.
I've scribbled and photographed something as it's difficult to explain just with words but no pictures.