Electronic Sensors Lab - The Hidden Circuits

GETTING TO REALLY KNOW YOUR ELECTRONIC SENSORS LAB IN BEHIND
THE SCENES

The Sensors Labs from Forrest Mims III has a very good console, but there are things that he forgot or avoided to talk about them. Its a great kit, and I have been using it for a long time for
radio science related experiments such as the Electromagnetic Field Receiver, if I were to build
this circuit on another breadboard or circuit board, its best that you need to read the bottom information that you may need to know on how to transfer these circuits to another PC board. Its
nothing secret, its things that should have been added or updated in the manual so you know how
the circuit really works and how its stable. If you do not follow the instructions that is in the manual or not be fully aware of the 4 small things in the kit, the circuit will operate erratically and not function
properly,. I recommend this to new hobbyists who just bought their own kit.

5 THINGS YOU NEED TO KNOW ABOUT YOUR LAB KIT

1. The Sensors Lab has a simple LED display circuit, this circuit is very important to learn and understand when you are building projects from the lab manual. The LED bargraph display has 3 parts to get it working normally. If it does not work, be sure to check the battery or go inside the console and replace the IC and also the 2 electronic components. There is also a Audio Transformer and also a buzzer which does not have to do anything with the LED dot bar circuit. The manual says that the LED display does suck up some juice, so its best to have a fresh 9 volt battery to keep it going. If you google LM3914 you will be surprised that there are some extra bonus applications you can use with the LED display console even use it to hook up an ipod or CD player to measure music such as a VU meter if worked right. - LM-3914 - Bar/Dot Display Driver IC - 2.2 uF 50 volt - Electrolytic Capacitor
- 1/8 watt 10k resistor.

2. The Sensors Lab has a resistors inside on the potentiometers that help reduce current
and the resistor values are 470 ohm resistors, there are 3 inside the kit. These resistors
are required to keep the circuit stable.

3. The Sensors Lab has a Magnet Sensor Switch which is only a Hall Effect transistor that has a
2.2 k resistor in between for to just to reduce current to avoid damage, which the manual should of let others know about that resistor inside. If you were about to build the circuit using this hall effect transistor you will need that resistor to be included to work properly.

4. The Sensors Lab has something out of the ordinary, but its something you need to know about
your sensors lab kit. The Rotation Sensor is just a DC motor and this motor is something you
can find out of a toy car or plane that can be used for your favorite project. Radio Shack has
these all the time. So now you know, its not an encoder found in radios or a potentiometer to
control voltage.

5. The Touch Sensor is just a circuit board that has the the pads divided that uses things like a
piece of foam to create pressure in the circuit.