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Is this true?

JimB

Super Moderator
Most Helpful Member
Looks like a load of nonsense to me.

JimB
 

MacIntoshCZ

Active Member
So he connect transistor and resistor in series with clock. Thats briliant energy saving circuit.
nope
 

resr1286

New Member
This circuit uses transistor half-biased, it works but the transistor limits the current and gets hot, nullifying the use of old Li-ion battery, which is another topic how to isolate good cells from bad ones, it's just easier to use good Ni-MH that are usually the same capacity and lasts as long if not even longer._
 

gophert

Well-Known Member
Most Helpful Member
Well, if you ever pulled an old laptop off a shelf, are the batteries still charged like when you put it away?
Rechargeable Lithium batteries generally have a self-discharge rate that is not good for long term power storage.

 

Zarish123

New Member
This circuit uses transistor half-biased, it works but the transistor limits the current and gets hot, nullifying the use of old Li-ion battery, which is another topic how to isolate good cells from bad ones, it's just easier to use good Ni-MH that are usually the same capacity and lasts as long if not even longer._
Here is why a transistor is used
 

MacIntoshCZ

Active Member

audioguru

Well-Known Member
Most Helpful Member
Yes, but clock will be slowed down. Probably wont work properly.
He only limit current....
Its nonsense
The transistor is an emitter-follower with a 0.65V base-emitter voltage drop and is biased with two identical-value resistors to reduce the 4.2V battery voltage to 2.1V for the base. Then the clock gets 2.1V - 0.65V= 1.45V like a 1.5V ordinary disposable battery. The clock motor is tiny and uses a tiny current.
When the battery charge is run down then it must be recharged or replaced.
 

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