Re: X10 device to detect open circuit or voltage drop

["Bob F" <bobnospam@xxxxxxxxx>]

Bob F wrote:
> codepug@xxxxxxxxx wrote:
>> On Nov 9, 6:17 pm, "Bob F" <bobnos...@xxxxxxxxx> wrote:
>>> code...@xxxxxxxxx wrote:
>>>> On Nov 1, 1:11 pm, nob...@xxxxxxxxxxxx (Dave Houston) wrote:
>>>>> "Greg (code...@xxxxxxxxx)" <code...@xxxxxxxxx> wrote:
>>>>>> Which X10 device would be used to detect a low voltage drop, or
>>>>>> open circuit ? It seems that the powerflash does the reverse.
>>>
>>>>> It might help if you tell us the specifics of what you want to do.
>>>>> No X10 module is designed to do exactly what you want but we may
>>>>> be able to come up with suggestions on how to use them or other
>>>>> devices to accomplish your goals.
>>>
>>>>> For example, many of the Smarthome modules will send an x10 code
>>>>> when the load they control is turned off.
>>>
>>>> I have snap style temperature sensors that are normally closed. I
>>>> want to detect when the
>>>> circuit opens, and be able to send an x10 signal to a red light.
>>>> The problem is that the
>>>> powerflash module only sends a lights ON signal when a circuit
>>>> closes. I do not have a
>>>> computer available in this location to interpret an OFF signal to
>>>> mean ON. What are my options ?
>>>
>>> You could use a resister in series with the sensor, fed by a power
>>> supply, with the powerflash module wired across the sensor. Thus, it
>>> will get voltage when the sensor opens.- Hide quoted text -
>>>
>>> - Show quoted text -
>>
>> Would you be able to elaborate further, since I am only familiar with
>> very basic electronics
>> and am using 3-snap sensors (normally closed) and is curently in
>> series. How does this get
>> wired ?
>
> I haven't done this, but I would imagine a 6-12 V AC or DC power
> supply would work. Wire the power supply through a 1000 ohm resister
> to the switch contacts, and wire the powerflash module to the
> contacts. Set the powerflash to switch position A.
>
> One wire of the power supply  and one contact of the powerflash
> connects to one end of your sensors. The other wire of the power
> supply connects to one lead of the resister. The other lead of the
> resister connects to the second end of your sensors, and the second
> contact on the powerflash.
> You could test the concept using a 9V battery in place of the power
> supply.
> The power supply can be a used one from an old used electronic device
> such as a phone, that connects it to the wall power. Make sure it is
> rated between 6 and 18 Volts.

The resister needs to be rated for power according to P=(VxV)/R. Maybe a 10,000
ohn resister would work better to reduce the power needed.