Switch Puzzle

Hmm, good but we're missing the ground. It is a split supply,

Vdd Vee ^ B1 B2 off Vee Vdd v

RL

would seem simple enough, center pins to vee & vcc outer pins to the cells.

would be easier.

(View with a fixed width font such as Courier)

---------------O |

+--------------------------------------+ | | | +----------------> |-3V | | | | O | | O O-------->+3V | | | | | +-----+---|--[B2+]------+-+----------> |0V | | | | +-->|

Google 'charge equalization'.

RL

Use 4P3T, see...

Newsgroups: alt.binaries.schematics.electronic Subject: Re: Switch Puzzle (on S.E.D) - SwapBatteries.pdf Message-ID:

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | |

Newsgroups: alt.binaries.schematics.electronic Subject: Re: Switch Puzzle (on S.E.D) - SwapBatteries.pdf Message-ID:

Or use 4PDT with break-before-make if you don't need a true OFF position.

...Jim Thompson

Hmmm, the output polarity is reversed when the switch is in the bottom position.

I've managed to figure out a working solution using a 4P3T slide switch, but doesn't this seems like overkill? I call it the spaghetti nightmare:

Vdd Mark Jones / Helios Studios A evsgs1602 at sneakemail.com | .--------------------------. .----. | | 4P3T | |+ | .----|---+---O O O O-----|-----.

----- '--|--+-|-----------/ ---------|--. | --- | | | .----O|| O|| ||O ||O-----|--|--|--. | B1 | | +--|-----||-/ || || -||---. | | | | '-------' | '--|----O|| O|| ||O ||O--|--|--|--|--+ | +--------/ ------+ | | | | .----------|-+--|----O O O O--|--' | | | |+ | | | .-----/ ------|--. | | |

----- | '--|--|---------------------|--|--' | | --- '----|--|---------------------|--' | V | B2 '--|---------+-----------' | Vee '------------------+---------|--------------------' Pos1: Vdd-B1-GND-B2-Vee | Pos2: Off ----- Pos3: Vdd-B2-GND-B1-Vee --- -

-M

Translated into slide switch...

Best regards, Spehro Pefhany

--- Based on his description, here's what he's looking for in one instance:

and in the other:

Which my circuit (and Jim Thompson's, which uses one less switch section) gives him.

Your circuit doesn't and, in fact, reverses the polarity of the battery into the load. Something, I'm sure, he _doesn't_ want to happen.

As a matter of fact, your circuit seems to be the common DPDT polarity reversing switch:

O--> +/- 1.5v | | | | +----------> OV | | | +----------------> -/+ 1.5V | |+ | | [BAT2] | | | | | O | | | +--> (View with a fixed width font such as Courier)

-- John Fields

Based on his description of the current system (switching the batteries by hand) I don't think he really wants or needs position 2. I think he is trying to describe a break-before-make switch.

(View with a fixed width font such as Courier)

DUAL BATTERY INVERTER

---------------O |

My error. I misread his original request and thought the he was swapping batteries and reversing them as well (a DPDT polarity reversing switch does the latter but not the former). I posted a corrected schematic when I realized that I had misunderstood the requirements. I apologize for any confusion my error may have caused.

Here is a battery swapper that is not also a battery reverser:

(View with a fixed width font such as Courier)

BATTERY SWAPPER

---------------O |

"John Fields" schreef in bericht news: snipped-for-privacy@4ax.com...

Let's add a schottky bridge:

Presto, a new and 'totally worthless idea'(TM) ;)