Rain Alarm (1 Viewer)

[Richard n Ann]

We've woke up in Benidorm 2 or 3 times with rain all over the bed and dripping through the Omnivent who knows if it got into the electrics but it's started the common switching off red light fault.

Anyway over the past 2 days I've been working on a rain alarm to fit into the Omnivent, quite pleased with the results so far, got to make more tests to make sure the evening dew doesn't set it off (got heaters behind the sensor, only 40ma ) I suppose the sensor will want cleaning every year but I'm up doing the fan filters anyway. I'm putting the sensor just under the lid so it won't get wet when the lid is down.

Circuit diagram will be available when I know it's perfected, I can maybe build a few while in lockdown

 

[Richard n Ann]

All finished, I tested the sensor in and out of the fridge for condensation and all is well, no false alarms but I suppose it won't get tested properly until we get a heavy dew and it's on the roof. The sensor feels slightly warm to touch so can't imagine dew settling on it.

Sensor pad on roof.

Board mounted, got a tiny green LED on it now.

The switches were hard to fit, I didn't want anything in the facia that would be attached by wires, so had to make a switch mount out of perspex and mount them just behind it, with a neatly cut square hole to access them. By just switching the sensor off the heaters remain on to dry the sensor and electrolysis stops

 

[Raul]

Well done for the rain sensors.
Velux does some nice rain sensors for their integra models. It shuts the window if it starts to rain. I have fitted few, and comes with extra wire and mounting plate. On the velux it fits on the flashing, it can be adapted to close any motorised skylights.

^{_{Subscribers  do not see these advertisements}}

 

[PhilandMena]

Cant you just look out the window ?

 

[Raul]

If you’re not there?

 

[Richard n Ann]

Cant you just look out the window ?

It's to wake us up hopefully

^{_{Subscribers  do not see these advertisements}}

 

[Nasher]

Nice job, I remember building one from my 'Phillips Electronic Engineer Kit' when I was about ten years old

How about linking it to a relay to shut the skylight (assuming it's motorised)?

 

[Richard n Ann]

Nice job, I remember building one from my 'Phillips Electronic Engineer Kit' when I was about ten years old

How about linking it to a relay to shut the skylight (assuming it's motorised)?

No it's a manual winder. Poverty model

 

[Richard n Ann]

There were black clouds about last night so I put the rain alarm on. Half way through dinner "pip pip pip pip!" I thought oh crap that's gone wrong somewhere then, but no, I went outside and there were tiny spots of rain in the air. Never heard it landing on the roof

Anyway just thought I'd bore you with last night's bit of excitement

^{_{Subscribers  do not see these advertisements}}

 

[Riverbankannie]

That is very neat with the switches.
We had to replace the control board last year and wanted to replace the PCB with simple on/off, in/out switches and resistors for speed control. Having got a working system on the dining room table, with the old motor, we abandoned the project and just bought new motor and PCB. We have kept the old one though for future attempts to go back to it. Your solution looks very neat.
Might be interested in one of your alarms as that is the vent that we leave open at night (but also during the day when out and about).

 

[Richard n Ann]

That is very neat with the switches.
We had to replace the control board last year and wanted to replace the PCB with simple on/off, in/out switches and resistors for speed control. Having got a working system on the dining room table, with the old motor, we abandoned the project and just bought new motor and PCB. We have kept the old one though for future attempts to go back to it. Your solution looks very neat.
Might be interested in one of your alarms as that is the vent that we leave open at night (but also during the day when out and about).

I haven't touched the fan speed controller the switches are for the rain sensor.

That's my next job though, it was unbearable last night in the heat I had it set to extract and the bloody thing kept switching off I thought it was the electronics at first because the motor sounds and runs fine, but when I switched it up to maximum last night it suddenly slowed an made a rumbling noise as if the bearings are getting dry I suppose first job then is oil the bearings with fully synthetic engine oil (I find it last longer)

Did you find out if yours was a pcb or motor problem?

 

[Riverbankannie]

I haven't touched the fan speed controller the switches are for the rain sensor.

That's my next job though, it was unbearable last night in the heat I had it set to extract and the bloody thing kept switching off I thought it was the electronics at first because the motor sounds and runs fine, but when I switched it up to maximum last night it suddenly slowed an made a rumbling noise as if the bearings are getting dry I suppose first job then is oil the bearings with fully synthetic engine oil (I find it last longer)

Did you find out if yours was a pcb or motor problem?

It was the PCB. The motor worked fine in all combinations of speed and direction with simple rocker switches and resistors.

I think we would find it too noisy to have on all night though so just use it when cooking. I have a very quiet John Lewis 12v USB 6inch personal fan by bed when very hot.

^{_{Subscribers  do not see these advertisements}}

 

[Richard n Ann]

I made this fan board for the skylight when it's hot, it's got a pwm speed controller on it so is very efficient, I turn it down at night until you can hardly hear it but it still brings in the (hopefully ) cool night air.

When we get home I'll remove the electronics off the kitchen fan and make another controller for that, we only ever use it on extract so I won't bother making it reversable. Also I don't know if you noticed but the fan blades are curved to scoop the air efficiently for extract, when you run them backwards, they work but are very inefficient.

 

[Richard n Ann]

Might be interested in one of your alarms as that is the vent that we leave open at night (but also during the day when out and about).

I can make you one when we get home

 

[Riverbankannie]

Thanks.
Husband says do you work for RR (being knowledgeable about fan blades) Derby? He did too.

^{_{Subscribers  do not see these advertisements}}

 

[Richard n Ann]

Thanks.
Husband says do you work for RR (being knowledgeable about fan blades) Derby? He did too.

No my trade is Refrigeration and AC, there are thousands of fan blades/motors involved that's why I didn't like the sound of the fan making that rumbling sound, mind by the time I got called out to one it had probably done 100's of thousands of run hours not like a few hours in a van ceiling

We used to work for companies that made parts for Rolls Royce like Bulwell Precision Engineering, and I remember another one not too far away that made the engine fan blades.. And one in Mansfield that made airbus wing struts (SPS aerospace? )