Bs2 power supply at 12v

Andres

hi my name is Andres

My question is about my input power supply toward the BS2. I will be supplying a 12V voltage and 2.80A maximum current to the Breadboard of the BS2.
So, what you think about the input power supply will damage the BS2 circuit if I use the breadboard of the BS2?

If my power supply is fine, then my second question is: Do you know how I can turn on and off the power supply depending the reading of the Sensor that come from the BS2?

I was thinking using the same pin that use the power supply, then I can make a program for just that pin to turn on and off.
Third question can be done.

Do you have similar programs?

Thank you

Mike Green

What breadboard do you mean? Most Parallax Stamp boards use a voltage regulator that can handle 12V if the heat produced is ok. The regulator takes any voltage above 5V and converts it to heat. The amount of heat depends on the amount of current actually supplied by the regulator. (Vinput - 5V) * Current = Power converted to heat. Most Stamp boards have a small heatsink attached to the voltage regulator which will help. If the regulator gets too hot, it will automatically turn itself off until it cools down.

The Stamp itself draws very little current. Most of the current (and heat produced by the regulator) depends on what you connect to the Stamp and where it draws its power.

The recommendation for a 6-9V power source is based on this heat issue so that heat production will not be a problem at the current drain supported by the regulator (0.8 to 1A typically).

Andres

Ok,

So, the breadboard that I am talking about is the one attached to BS2. So, the max. heat produces will be (12V)*(2.80A) = 33.6 Watts.
Do you think the heat production is fine for this BS2 breadboard.

Do you know how I can turn on and off the pin that input power supply is using from the BS2 breadboard?

I was thinking of using a program to turn on and off that pin depending the reading of a sensor.Do you have similar examples for this goal.

Andres

The idea is that I will be supplying power to a water pump that will connect to the BS2 breadboard. This water pump needs 12V Voltage and .620A current to start working.
So I need the BS2 breadboard to control the water pump.

Franklin

You can't output 12v on a pin of the stamp. It would help if you were to draw the circuit you are planning to build so we could see just what you are talking about.
www.parallax.com/Default.aspx?tabid=362 Here are the documentation and study guides for Basci Stamps, start a t the top and work your way down.

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- Stephen

Andres

The idea is that I will be supplying power to a water pump that will connect to the BS2 breadboard. This water pump needs 12V Voltage and .620A current to start working.
So I need the BS2 breadboard to control the water pump. Also, I will be connecting a sensor to tell the water pump to turn off or On depending the reading of the sensor.

COMPONENTS

12V Battery with a max current of 2.80A
12v Water Pump with input current of .620A
IR Sensor
BS2

Mike Green

That's a very different picture than you had originally presented.

Look at Nuts and Volts Column #6 for a discussion on controlling small motors, relays, and solenoids from a Stamp using a switching transistor. In this case, you can easily run the Stamp from 12V since there's very little current involved. The Stamp itself draws perhaps 10mA. The IR Sensor draws a few mA. The switching transistor will require 10-20mA from the Stamp. That's a total of maybe 25-30mA so the regulator would have to dissipate (12V - 5V) * 0.03A = .21W which is less than a 1/4 W resistor might produce. The motor is powered directly from the 12V supply with a switching transistor as described in the Column.

Nuts and Volts index: www.parallax.com/tabid/272/Default.aspx

Andres

Sorry for the misunderstand, now I have a better understanding how to put everything together.

Thank very much Mike