I would like to use Analog Coprocessor Pioneer Kit in order to address the following problem:
Electric boxes are especially used for outdoor applications and because of that sometimes it can be bad for the device. When either temperature or humidity conditions are not optimal then maintaining the box can cause serious damage. Since an electric box is under high voltage any drop of water on “hot” elements can be fatal for them and it is the best way to harm the device inside the box. Moreover it can be also dangerous for an operator who maintains it.
Conditions that are perilous to be considered:
- Electric components inside the box work under the both high temperature and humidity conditions.
- Outside temperature is low. While maintaining the box by an operator, temperature inside the box is higher.
- Well known is a situation where components inside an electric box are being cooled down quite quickly and in fact we can observe occurrence of the “dew point” effect.
- The “dew point” can cause appearing of water drops on “hot” elements mentioned earlier. In result it can be a reason to short circuit.
1. Temperature and humidity sensors can calculate when the “dew point” effect is possible based on the surrounding conditions.
2. Indication on the front panel if opening the box is safe - for example by using LED signal. (Red - danger do not open / Green - good to operate)
3. When it’s red then an operator is able to use a ambient light sensor as switch (cover the sensor by finger will behave as pressing the button). It will allow him to activate an internally mounted fan and heater to rise temperature and allow to circulate the air faster inside the electric box. In result the “dew point” can be decreased to a level being safe for the device inside.SCHEMATIC:
I have based my project using the PSoC Analog Coprocessor pioneer kit (CY8KIT-048).
Main operation is related to Dew Point calculation. I have used the formula described in one of the application note from Sensirion company www.sensirion.comRESULT:
Measure the temperature inside box (DieTemp sensor) and outside box (thermistor)
Measure humidity inside the box
Calculate the dew point occurrence if the temperature inside box will drop to outside level ( door open by operator ).
If unsafe conditions can occur Red LED is on
If the safe conditions present then Green LED is on
In the project I have also used the ALS sensor to work as a button (decided to do it because it provide a good galvanic isolation). Covering the ALS sensor will allow to turn on the AC fan and heater inside the box and allow to remove the unsafe conditions. Operator can activate it only when the danger conditions are present.