On Wed, 19 Nov 2008 11:34:51 -0800 (PST), Efthimios
<eangelopou...@gmail.com> wrote: >Imagine a device working at 1 Volt.
>I what to protect it from a voltage spike of 50 to 100 Volts.
You'll need to define your requirements for "protect." No over-voltage protection can react in zero time to clamp the voltage to (V-limit plus exactly 0 volts).
>Does any know how to do this in a cheap way???
Knowing how to do it cheaply requires more knowledge of what device and in what environment. Guessing the operating and maximum allowable parameters of an arbitrary device isn't productive.
> On Wed, 19 Nov 2008 11:34:51 -0800 (PST), Efthimios
> <eangelopou...@gmail.com> wrote: > >Imagine a device working at 1 Volt.
> >I what to protect it from a voltage spike of 50 to 100 Volts.
> You'll need to define your requirements for "protect." No over-voltage > protection can react in zero time to clamp the voltage to (V-limit plus > exactly 0 volts).
> >Does any know how to do this in a cheap way???
> Knowing how to do it cheaply requires more knowledge of what device and > in what environment. Guessing the operating and maximum allowable > parameters of an arbitrary device isn't productive.
> -- > Rich Webb Norfolk, VA
-The spike has a duration of 0.2 to 0.3 seconds. -The device to be protected is a sensor with operation voltage of 1 Volt and maximum allowed 1.5 Volts. -The sensor draws a less than 0.1 milliamp. -The device works under normal room temperature and humidity conditions -Cost preferably about a dollar.
Efthimios wrote: > Rich Webb <bbew...@mapson.nozirev.ten> wrote: > > Efthimios <eangelopou...@gmail.com> wrote: > > >Imagine a device working at 1 Volt.
> > >I what to protect it from a voltage spike of 50 to 100 Volts.
> > You'll need to define your requirements for "protect." No over-voltage > > protection can react in zero time to clamp the voltage to (V-limit plus > > exactly 0 volts).
> > >Does any know how to do this in a cheap way???
> > Knowing how to do it cheaply requires more knowledge of what device and > > in what environment. Guessing the operating and maximum allowable > > parameters of an arbitrary device isn't productive.
> > -- > > Rich Webb Norfolk, VA
> -The spike has a duration of 0.2 to 0.3 seconds.
But of what ENERGY ? That's critical. And source impedance ?
Plus, that's a bugger of a voltage range to protect as it happens !
On Wed, 19 Nov 2008 11:34:51 -0800 (PST), Efthimios
<eangelopou...@gmail.com> wrote: >Imagine a device working at 1 Volt.
>I what to protect it from a voltage spike of 50 to 100 Volts.
>Does any know how to do this in a cheap way???
Protection of power rails and signal lines pose differing problems. You'd have to be more specific about the actual node on the specific device that was threatened.
> >I what to protect it from a voltage spike of 50 to 100 Volts.
-The spike has a duration of 0.2 to 0.3 seconds. -The device to be protected is a sensor with operation voltage of 1 Volt and maximum allowed 1.5 Volts. -The sensor draws a less than 0.1 milliamp. -The device works under normal room temperature and humidity conditions -Cost preferably about a dollar.
** Use a bridge rectifier.
Just short the + and - terminals together and connect the AC ones across your sensor - this will clamp the DC rail to 1.5 vols. A 1 or 2 amp rated bridge costs about $1 ( DIL ones are cheapest ) and will survive 5 amps or more for 0.3 seconds.
Your problem if there is no series impedance limiting the current to a few amps.
> > >I what to protect it from a voltage spike of 50 to 100 Volts.
> -The spike has a duration of 0.2 to 0.3 seconds. > -The device to be protected is a sensor with operation voltage of 1 > Volt and maximum allowed 1.5 Volts. > -The sensor draws a less than 0.1 milliamp. > -The device works under normal room temperature and humidity > conditions > -Cost preferably about a dollar.
> ** Use a bridge rectifier.
> Just short the + and - terminals together and connect the AC ones across > your sensor - this will clamp the DC rail to 1.5 vols. A 1 or 2 amp rated > bridge costs about $1 ( DIL ones are cheapest ) and will survive 5 amps or > more for 0.3 seconds.
> Your problem if there is no series impedance limiting the current to a few > amps.
Yes, can't fault that one other than possible junction capacitance. The OP doesn't say how fast the signal is.
