o0ICE0o
0
- Joined
- Jul 26, 2009
- Messages
- 340
- Points
- 0
I need a circuit that stops if the V going through it drops below 5.8.
Does anybody know hot to do this?
Thanks.
:thinking:
Does anybody know hot to do this?
Thanks.
:thinking:
LPF Donation via Stripe | LPF Donation - Other Methods
Links below open in new window
ArcticMyst Security by Avery
How to break the circuit when V drops below 5.8?
- Thread starter o0ICE0o
- Start date
HIMNL9
0
- Joined
- May 26, 2009
- Messages
- 5,318
- Points
- 0
depend, you need more easyness or accuracy ?
For accuracy, you need a precise Vref and a comparator, if instead you want an easy and quick circuit, just use a pair of transistors (and if the space is not a problem, a relais), and a zener diode ..... like these ones, not extremely precise, but simple to build also on-the-fly.
These ones opens the positive line when the voltage go under the zener value, and re-close it when increase again .... the first use a pair of transistors, the second a transistor and a relais
-
These ones do the same, but for close the circuit you must press the button ..... then it stay on til the voltage go under the zener value, and then open the circuit, for close it again you need to push the button again ..... first with transistors, second with transistor and zener.
-
Advantages and disadvantages ..... the ones with transistors, you need to use a power PNP transistor that hold the current that you need to pass through it, and also cause a little 0,6V dropout, but can be built very compact ..... the second type, with the relais, are biggrt (it depend from the relais) and you must use a relais with coil working voltage adequate (and if the line is powered with 12 V or more, i doubt it remain turned on til 6V, but this depend from the relais, some types do it, someothers not), but the power that you can drive is limited only from the contact of the relais.
For accuracy, you need a precise Vref and a comparator, if instead you want an easy and quick circuit, just use a pair of transistors (and if the space is not a problem, a relais), and a zener diode ..... like these ones, not extremely precise, but simple to build also on-the-fly.
These ones opens the positive line when the voltage go under the zener value, and re-close it when increase again .... the first use a pair of transistors, the second a transistor and a relais
These ones do the same, but for close the circuit you must press the button ..... then it stay on til the voltage go under the zener value, and then open the circuit, for close it again you need to push the button again ..... first with transistors, second with transistor and zener.
Advantages and disadvantages ..... the ones with transistors, you need to use a power PNP transistor that hold the current that you need to pass through it, and also cause a little 0,6V dropout, but can be built very compact ..... the second type, with the relais, are biggrt (it depend from the relais) and you must use a relais with coil working voltage adequate (and if the line is powered with 12 V or more, i doubt it remain turned on til 6V, but this depend from the relais, some types do it, someothers not), but the power that you can drive is limited only from the contact of the relais.
Attachments
