bike light riddle

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Guest

Sun Jul 28, 2013 10:46 pm

I have a bicycle light, Opticube, standard unit,
single button, uses 2 AA batteries.

operation:
1. Push button, light on.
2. Push again, hold 2 seconds, off.

or:
1. Push button, light on.
3. Push again, hold 2 seconds, off.

But when the batteries are low, the
'hold, then off' time lengthens to 5 seconds.

What's the timing circuit?

--
Rich

Jasen Betts
Guest

Mon Jul 29, 2013 10:13 am

On 2013-07-28, r_delaney2001_at_yahoo.com <r_delaney2001_at_yahoo.com> wrote:
Quote:
I have a bicycle light, Opticube, standard unit,
single button, uses 2 AA batteries.

operation:
1. Push button, light on.
2. Push again, hold 2 seconds, off.

or:
1. Push button, light on.
3. Push again, hold 2 seconds, off.

But when the batteries are low, the
'hold, then off' time lengthens to 5 seconds.

What's the timing circuit?

pronbably a 4 bit microcontroller.

--
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Michael Black
Guest

Wed Jul 31, 2013 2:31 pm

On Mon, 29 Jul 2013, Jasen Betts wrote:

Quote:
On 2013-07-28, r_delaney2001_at_yahoo.com <r_delaney2001_at_yahoo.com> wrote:
I have a bicycle light, Opticube, standard unit,
single button, uses 2 AA batteries.

operation:
1. Push button, light on.
2. Push again, hold 2 seconds, off.

or:
1. Push button, light on.
3. Push again, hold 2 seconds, off.

But when the batteries are low, the
'hold, then off' time lengthens to 5 seconds.

What's the timing circuit?

pronbably a 4 bit microcontroller.

when the batteries are getting weak.

Michael

Guest

Thu Aug 01, 2013 12:33 am

On July 31, 2013, Michael Black wrote:
Quote:
I have a bicycle light, Opticube, standard unit,
single button, uses 2 AA batteries.
operation:
1. Push button, light on.
2. Push again, hold 2 seconds, off.
or:
1. Push button, light on.
3. Push again, hold 2 seconds, off.
But when the batteries are low, the
'hold, then off' time lengthens to 5 seconds.
What's the timing circuit?

pronbably a 4 bit microcontroller.

Could be.
But I thought a microprocessor, with its support
components, would be overkill, too costly, for a
cheap consumer item. Especially with such simple function.

Quote:
down longer when the batteries are getting weak.

Both.

--
Rich

Jasen Betts
Guest

Thu Aug 01, 2013 8:48 am

On 2013-07-31, r_delaney2001_at_yahoo.com <r_delaney2001_at_yahoo.com> wrote:
Quote:
On July 31, 2013, Michael Black wrote:
I have a bicycle light, Opticube, standard unit,
single button, uses 2 AA batteries.
operation:
1. Push button, light on.
2. Push again, hold 2 seconds, off.
or:
1. Push button, light on.
3. Push again, hold 2 seconds, off.
But when the batteries are low, the
'hold, then off' time lengthens to 5 seconds.
What's the timing circuit?

pronbably a 4 bit microcontroller.

Could be.
But I thought a microprocessor, with its support
components, would be overkill, too costly, for a
cheap consumer item. Especially with such simple function.

there's plenty of microcontrollers that'll run on anything between 1.8
and 3.3V and need no external parts, eg: ATTINY4-TSHR or
PIC10LF320-I/OT under a buck in small quantities, much cheaper in lots
of 100000 as bare dice for chip-on-board construction.

Quote:
down longer when the batteries are getting weak.

"what's the timing circuit"

It's a microcontroller, the clock is probably the on-chip RC clock,
it's slower to turn off possibly because the designer intends that
behaviour as a warning that the batteries are low. it's better (and
easier) to warn of low batteries at turn-off

--
⚂⚃ 100% natural

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Guest

Sat Aug 03, 2013 2:31 am

On August 1, 2013, Jasen Betts wrote:
Quote:
I have a bicycle light, Opticube, standard unit,
single button, uses 2 AA batteries.
operation:
1. Push button, light on.
2. Push again, hold 2 seconds, off.
or:
1. Push button, light on.
3. Push again, hold 2 seconds, off.
But when the batteries are low, the
'hold, then off' time lengthens to 5 seconds.
What's the timing circuit?

pronbably a 4 bit microcontroller.

But I thought a microprocessor, with its support
components, would be overkill, too costly, for a
cheap consumer item. Especially with such simple function.

there's plenty of microcontrollers that'll run on anything
between 1.8 and 3.3V and need no external parts, eg: ATTINY4-TSHR
or PIC10LF320-I/OT under a buck in small quantities, much cheaper
in lots of 100000 as bare dice

down longer when the batteries are getting weak.

It's a microcontroller, the clock is probably the on-chip
RC clock, it's slower to turn off possibly because the
designer intends that behaviour as a warning that the batteries
are low. it's better (and easier) to warn of low batteries at turn-off

Deliberately? Possible, but seems odd.

These chips require no external oscillator?
How does it know the battery is low?

It will drive a FET switch (for the bulb) without
a buffer? What are the minimum necessary external
components?

--
Rich

Michael Black
Guest

Wed Aug 07, 2013 2:03 am

On Fri, 2 Aug 2013, r_delaney2001_at_yahoo.com wrote:

Quote:
On August 1, 2013, Jasen Betts wrote:
I have a bicycle light, Opticube, standard unit,
single button, uses 2 AA batteries.
operation:
1. Push button, light on.
2. Push again, hold 2 seconds, off.
or:
1. Push button, light on.
3. Push again, hold 2 seconds, off.
But when the batteries are low, the
'hold, then off' time lengthens to 5 seconds.
What's the timing circuit?

pronbably a 4 bit microcontroller.

But I thought a microprocessor, with its support
components, would be overkill, too costly, for a
cheap consumer item. Especially with such simple function.

there's plenty of microcontrollers that'll run on anything
between 1.8 and 3.3V and need no external parts, eg: ATTINY4-TSHR
or PIC10LF320-I/OT under a buck in small quantities, much cheaper
in lots of 100000 as bare dice

down longer when the batteries are getting weak.

It's a microcontroller, the clock is probably the on-chip
RC clock, it's slower to turn off possibly because the
designer intends that behaviour as a warning that the batteries
are low. it's better (and easier) to warn of low batteries at turn-off

Deliberately? Possible, but seems odd.

These chips require no external oscillator?
How does it know the battery is low?

It will drive a FET switch (for the bulb) without
a buffer? What are the minimum necessary external
components?

Chances are good that it may be some dedicated IC in there. If someone an

cook up enough demand, it's simpler for a dedicated IC than everyone
working on their own.

I have some single LED "bicycle lights" that are smaller than a 9v battery
and you attach to the handlebars with the included elastic. They cost
\$3.75 Canadian. The first one I bought, it had slow flash, fast flash and
steady on, you'd press the button and advance the mode, then another press
ona off. The mroe recent ones do away with one of the flash modes, so
it's only continuously on or flashing. At that price, you can't spend
much time adding parts to a circuit board, so chances are good it's
dedicated to it. For all I know, it may be what's used in the bigger LED
bike lights, which of course have a similar ability to flash and stay on,
and use the on/off button for the same function.

So if it's a dedicated IC, chances are good as much as possible goes in
the actual IC (which would just be an expoxy blob).

Michael

Kevin McMurtrie
Guest

Wed Aug 07, 2013 5:23 am

r_delaney2001_at_yahoo.com wrote:

Quote:
I have a bicycle light, Opticube, standard unit,
single button, uses 2 AA batteries.

operation:
1. Push button, light on.
2. Push again, hold 2 seconds, off.

or:
1. Push button, light on.
3. Push again, hold 2 seconds, off.

But when the batteries are low, the
'hold, then off' time lengthens to 5 seconds.

What's the timing circuit?

--
Rich

The controller clock might be driven from the switching power supply
signal, either intentionally or not.

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