Electrical specs?

murmichel · February 19, 2018, 7:33am

I’m looking for a bit of documentation regarding the electrical specs.

Automat:

What is the voltage used to drive the solenoids (or other actuators)?
What is the max current?
Is there some kind of protection against over current or short circuit?

Solenoids:

Rated voltage?
Current consumption?

johannes · February 19, 2018, 9:32am

@murmichel good that you are asking about this information.

dadamachines - automat specs:

Input

USB Powered - only for development / hacking without Actuators connected.
DC Powered - Power Supply 9V-24V - DC Barrel Plug 2.5 x 5.5mm Center Positive - 8A max current (protected by 5x20mm Cartridge Fuse (Feinsicherung)
The Power Supply coming with the automat toolkit has 24V - 160W - 6.6A

Output

DC Outputs are always the same voltage you feed the automat - each Channel is limited to 1.4A current
The switching Transistor / MOSFETs for the Outputs are protected (Overload protection, Short circuit protection, Overvoltage protection, Current limitation and Thermal shutdown with auto restart)
Each Output has a Flyback Diode for protection against inductive loads

FYI added this info to the dadamachines website as well: https://dadamachines.com/getstarted/automat-specification/

dadamachines - automat toolkit - solenoids

24V - 0.5A - 35% duty cycle (http://www.thesolenoidcompany.com/glossary)

murmichel · February 19, 2018, 10:25am

Thanks.

To be clear, is the output voltage (roughly) the same as the input voltage? I.e., with a 24V power supply, do I get 24V at the outputs?

johannes · February 19, 2018, 10:32am

@murmichel Yes. The Outputs are the same voltage you feed the automat. The automat is switching the Ground connection.

Schematic layout of the Output Channel(s)… looks like this.

murmichel · February 23, 2018, 2:48pm

Can someone with a better understanding of EE than me explain whether/why it is a good idea to switch the ground connection?

I would have expected that the supply voltage were switched. Considering that ground or something close to it is everywhere, there’s a failure case were the supply voltage is present at a solenoid and the other connector inadvertently touches ground.