Power usage USB sticks

When I bought a new 64GB Sandisk UltraFit USB stick and used it, it got very hot, even when it was not used. I compared it to a 32GB Transcend JetFlash USB stick, which didn’t get so hot. So I began to measure the power consumption: Power consumption according to MacOS: Sandisk: 896 mA Transcend: … Continue reading “Power usage USB sticks”

When I bought a new 64GB Sandisk UltraFit USB stick and used it, it got very hot, even when it was not used. I compared it to a 32GB Transcend JetFlash USB stick, which didn’t get so hot. So I began to measure the power consumption:

Power consumption according to MacOS:

Sandisk: 896 mA
Transcend: 304 mA

Power consumption according to a Brennerstuhl ammeter by plugging the sticks into a charger and measuring the consumption:

Sandisk: 0.07W
Transcend: 0.02W

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So the power consumption of the Sandisk USB stick is significant higher. E.g. according to these values a powerbank with 6000 mAh would be drained in about seven hours only by powering the USB stick without reading or writing anything. That was a little bit unexpected to me and will reduce the time one can use it with a notebook while running on battery power.

Transferring a domain

Recently I transferred a domain from one provider to another (Server4You) and found it to be very fast and simple. After canceling the contract with the old provider it provided an AuthInfo Code that I had to give to the new provider (I had to enter it on their website). Afterward the transfer was automatically performed … Continue reading “Transferring a domain”

Recently I transferred a domain from one provider to another (Server4You) and found it to be very fast and simple. After canceling the contract with the old provider it provided an AuthInfo Code that I had to give to the new provider (I had to enter it on their website). Afterward the transfer was automatically performed in less than two hours without any interruption. I had already set the new IP for that domain when using the old provider so the IP stayed the same during the transfer.

Home automation with KNX

Using KNX it is possible to build a flexible way to control lights and shutters of a house. This will give a short exemplary overview what is necessary to build and program such a system. Hardware To build a working KNX system you need at least a power supply with a choke, an actuator, a touch … Continue reading “Home automation with KNX”

Using KNX it is possible to build a flexible way to control lights and shutters of a house. This will give a short exemplary overview what is necessary to build and program such a system.

Hardware

To build a working KNX system you need at least a power supply with a choke, an actuator, a touch sensor and a way to program it, e.g. using the Wiregate computer and a USB-KNX interface. Then you can extend this system using further actuators and touch sensors.

In this example a lot of MDT devices are used because they are cheap and flexible. But you can also choose from a broad variety of manufacturers because the KNX standard makes the devices compatible to each other. Here is an example list:

Power supply e.g. from Eibmarkt

Power supply and choke
Power supply, choke and line coupler

Switch actuator for switching lights, e.g. MDT AKK-1616.02 for 16 lights.

Switch actuator
Switch actuator MDT AKK-1616.01

Touch sensors e.g. from Berker.

Computer for programming the KNX system and for performing time dependent tasks. E.g. the Wiregate computer with a USB-KNX interface.

Windows PC with ETS software. It is needed to assign addresses and actions to the KNX devices. You can get the Lite version (which supports up to 20 KNX devices in each project) for free by completing the ETS eCampus online course.

 

That’s all what is needed to build a very small but working KNX network. Just connect the power supply, switch actuator and touch sensors to each other as documented and as you have learned in the ETS eCampus online course. Then connect the Windows PC and the Wiregate computer to the same network. Start the ETS and connect it to the Wiregate. Load the MDT and Berker product databases into the ETS software so that it knows which parameters your devices support.

Then assign addresses to your devices and configure them to communicate with each other. Everything you need to know was explained in the ETS eCampus online course. I will provide some screenshots here later.

When you tap one of the touch sensors, it will send a group address onto the KNX bus. The switch actuator will listen to that group address and switch the light on or off. That means after everything has been programmed, no computer is necessary for these simple tasks. Only for more complex tasks like turning the lights off or on at a certain time you need a computer. The Wiregate computer makes it easy to build your own automation solutions by providing a web interface that allows you to create small Perl scripts that react on group addresses or that are automatically started at a regular interval.