How are the V/I ?power source (24 Watts Max)
Use two 555 or one 556, the first 555 is a monostable multivibrator when it triggered then it will turn on for 15 seconds, and the second 555 is a astable multivibrator to drive a buzzer, works as 2 Hz oscillator.A DC speaker to sound intermittently for 15 seconds.
V/I?How are the V/I ?
Use two 555 or one 556, the first 555 is a monostable multivibrator when it triggered then it will turn on for 15 seconds, and the second 555 is a astable multivibrator to drive a buzzer, works as 2 Hz oscillator.
555 monostable multivibrator.
555 astable multivibrator.
V = Voltage , power supplyV/I?
V = Voltage , power supply
I = current, A, mA
How many volts of the circuit? (5V,9V,12V,24V)
How much current (mA) the circuit draw?
Scott, i'm not sure if I need a converter. I do appreciate your response above, but I guess I have to understand how to tie it all together.12V Power source disable → 12V Battery on → 0.1uF/25V → npn inverter → 15S 555 monostable multivibrator → 2 Hz 555 astable multivibrator → 12V Buzzer
>USB charger
Is this needs to use a dc-dc (5V to 12V) converter?
What component would make the battery go on when the device receives no power from the source?12V Power source disable → 12V Battery on → 0.1uF/25V → npn inverter → 15S 555 monostable multivibrator → 2 Hz 555 astable multivibrator → 12V Buzzer
>USB charger
Is this needs to use a dc-dc (5V to 12V) converter?
The device is what I'm trying to build.What is the "device" that is being powered by the source or battery?
What is the battery voltage?when the power source (24 Watts Max) is disabled and then a battery takes over.
Hi Alec,What is the battery voltage?
How does disabling the power source cause the battery to take over? Do you have a circuit for doing this automatically?
Of course, once I figure it out.will you show us the result???
It almost has to be like tamper switch. When it detect no power from the source, it must switch on VIA the battery.If the battery is 12V then you will need a 5V to 12V converter.
The circuit below shown the trigger function and alarm(1 Hz), you can adjust the frequency of alarm, please refer to the link, I changed the bjt to N MOSFET for the power consumption of battery and using the cmos 555.
You still need to decide how to active the battery, use plug or switch, or connected all the time but use some voltage detector to detect?
View attachment 135807
555 Monostable Circuit Calculator.
555 Astable Circuit Calculator.
by Jake Hertz
by Duane Benson
by Duane Benson
by Duane Benson