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The Batterizer circuit is more widely known as joule thief [1]. It's a boost converter that produces a constant output voltage regardless of the battery voltage

The Batterizer circuit is more widely known as joule thief [1]. It's a boost converter that produces a constant output voltage regardless of the battery voltage. Some sort of similar switching power supply is standard in things like cell phones and laptops. For cheap toys, cost is key and the circuit would be too expensive. "5 times more battery life" is kind of crazy though. Alkaline batteries start falling off quickly as they become discharged - in fact, this is a prized feature of the chemistry as the voltage stays pretty level through most of the life of the cell [2]. What surprises me is that they can build the Batterizer for $2.50. That seems awfully low for a completed product like that. How many amps can it handle? Even at the $2.50 price point, you'd be better off buying NiMH cells. That would do much more for the environment than the Batterizer. [1] https://en.wikipedia.org/wiki/Joule_thief https://en.wikipedia.org/wiki/Joule_thief [2] http://www.powerstream.com/AA-tests.htm http://www.powerstream.com/AA-tests.htm

rasz_pl 11y ago
> standard in things like cell phones and laptops or 25 year old toys like Game Boy http://fms.komkon.org/GameBoy/Tech/PowerAndCart.gif http://fms.komkon.org/GameBoy/Tech/PowerAndCart.gif and gameboy color: https://www.youtube.com/watch?v=yuaA-rUBmEc https://www.youtube.com/watch?v=yuaA-rUBmEc both cutoff voltage <1v per cell
cnvogel 11y ago
I think the idea of a "jule thief" basically is a extremely low power boost converter to run a LED as a nightlight on the remaining few % of an otherwise depleted battery. A standard switching power converter wouldn't be called that way, even when modern chips used for that purpose obviously try hard to be as power efficient as possible. In a typical circuit nowadays you'd also avoid the use of a two coil transformer, and just have a "one coil" inductor to save on copper. The second winding is needed to control the.transistor in the simple circuit shown on Wikipedia. Also the simple circuit doesn't provide for any regulation. The more elaborate gameboy schematicsuses mentioned in the parallel comment to mine uses feedback (look for the 4.7v Zener pulling down the transistor) to accomplish that. But of course nowadays one would use a simple 4 to 8 pin IC integrating almost everything except the inductor.

rasz_pl 11y ago

> standard in things like cell phones and laptops or 25 year old toys like Game Boy http://fms.komkon.org/GameBoy/Tech/PowerAndCart.gif http://fms.komkon.org/GameBoy/Tech/PowerAndCart.gif and gameboy color: https://www.youtube.com/watch?v=yuaA-rUBmEc https://www.youtube.com/watch?v=yuaA-rUBmEc both cutoff voltage <1v per cell

cnvogel 11y ago

I think the idea of a "jule thief" basically is a extremely low power boost converter to run a LED as a nightlight on the remaining few % of an otherwise depleted battery. A standard switching power converter wouldn't be called that way, even when modern chips used for that purpose obviously try hard to be as power efficient as possible. In a typical circuit nowadays you'd also avoid the use of a two coil transformer, and just have a "one coil" inductor to save on copper. The second winding is needed to control the.transistor in the simple circuit shown on Wikipedia. Also the simple circuit doesn't provide for any regulation. The more elaborate gameboy schematicsuses mentioned in the parallel comment to mine uses feedback (look for the 4.7v Zener pulling down the transistor) to accomplish that. But of course nowadays one would use a simple 4 to 8 pin IC integrating almost everything except the inductor.