12V and OpenSprinkler DC

[admin]

Some customers have noticed that the OpenSprinkler when using a 12V power pack, e.g. a DIN rail power pack, gets quite hot.

A voltage regulator is used internally, which reduces the voltage from 12V to 5V. This voltage regulator is rated up to 15V and can indeed get very hot. The connected solenoid valves do not load the voltage regulator because they are controlled by a different circuit.

However, it becomes problematic when other consumers come into play and the outside temperature rises at the same time.

Consumers that can be connected directly are sensors, A2D converters and the network adapter. The network adapter in particular draws 150mA and is therefore one of the main consumers.

Due to the higher power consumption, the temperature also increases and this can lead to the voltage converter burning out. Likewise if the voltage is not 12V but 13-14V.

For this reason, we recommend using an external voltage converter in this case, which can regulate the voltage down to 7,5V.

For example, there is a “Step-Down Converter Adjustable 10-5V 36A Voltage Regulator Converter Module Kit LED” on eBay for EUR 5, with which the voltage can be regulated precisely to 7,5V. This can then be attached to the housing with double-sided adhesive tape or Velcro.

The temperature can be checked as follows: During operation, the contact opening of the OpenSprinklers check with a temperature measuring device. Alternatively, touch it briefly with your finger, don't worry, there isn't much tension here. >40° is actually too much and you should use a voltage converter.

[Nachtigall]

Thanks for the information. A question: This also applies to the OSPi?

[admin]

No, that OSPi uses a 24VAC-DC converter. If the power consumption becomes too high, the Raspberry PI reboots.

The OSPi up to version 1.44 can deliver max 5V/0,5A = 2,5Watt power,

of OSPi from 1.5 can deliver max 5V/2A = 10Watt power.

[Author]

Posts