Schematic for a variable timer
Schematic for a variable timer
(OP)
Hello,
I need a schematic for a timer circuit (preferably using a low voltage 555 timer) that will give an output at 10 minutes and then another output 1 hour later when triggered. The output will be used to drive a beeper. Supply voltage for the whole circuit is to be at 1.5V and power consumption should be minimal since the whole circuit will be battery-powered. Timing accuracy is not critical. A +/- 2% error is acceptable.
Any help given will be much appreciated.
Nang
I need a schematic for a timer circuit (preferably using a low voltage 555 timer) that will give an output at 10 minutes and then another output 1 hour later when triggered. The output will be used to drive a beeper. Supply voltage for the whole circuit is to be at 1.5V and power consumption should be minimal since the whole circuit will be battery-powered. Timing accuracy is not critical. A +/- 2% error is acceptable.
Any help given will be much appreciated.
Nang





RE: Schematic for a variable timer
If small number : trade off more battery . Use dc-dc
to raise VTG, use XTAL/CMOS COUNTER.
Are the times fixed or programmable ? How much battery lifetime is OK ? Volume limit ?
Need schematics ? Give a FAX#.
<nbucska@pcperipherals.com>
RE: Schematic for a variable timer
RE: Schematic for a variable timer
Not with 2% accuracy !
<nbucska@pcperipherals.com>
RE: Schematic for a variable timer
What I need is something simple and low-cost. Two months battery life at least. I'm looking at button-type batteries as used in watches. The circuit doesn't need to be active all the time. The circuit only turns on when a push button switch is pressed. And the alarm goes off twice at the fixed times of 10 min. and then 1 hour later and the circuit should then turn off.
Nbucska, my fax# is:
Country code:60
Number is: 4-2628690
Thanks.
Nang
RE: Schematic for a variable timer
sequences do your battery have to survive ?
With CMOS logic, you will need about 4 or more IC-s
Do you have enough space ?
It could be smaller with microcontroller if power is acceptable.
If you need only one, why can't you use larger battery ?
<nbucska@pcperipherals.com>