Automates
In this section I’m presenting a few useful automates. As said before, the electronically schematic is in each case a simple one. For better results you have to search “deeper”.
The first example is a Metal detector. It is design for a good mobility, the energy supply is a small 9V battery and the emitter is an earphone. You should pay attention to the coil manufacture. They must to be done precisely.
The next one is a liquid detector. I have use two of them to control the water level in a big barrel. The output gives sufficiently current for controlling a relay. I used one detector for the lower side of the barrel. It is the “barrel empty” level, and the second detector for the upper side “barrel full”. The relays control a 220V pump that fill up the barrel when the water has rich the lower level.
If you want to eliminate a mechanical switch, you can build the current schematic. As you know a relay switching time are very short mili-seconds. That mean you will have a clear on-off switching for your apparatus and you eliminate the mechanical wear. The touch buttons are made from two small metallic plates displayed at 1 mm to another. The finger resistance is good enough to set T1 or T2 in conduction.
Here is presented a multifunctional power supply for laboratory use. You can get a differential voltage (+/-24V) just by setting a switch. The maximal voltage is approximate to 40V.
Lights applications
This section is dedicated to lights application. It is about disco lights, how to light your perimeter when the dark is coming, audio signal level controlling. Some of the examples are made with LED’s other with normal bulbs at small voltages. If you want to use 220V bulbs you have to build an extra tyristor (transistor) schematic.
When you are pressing the B button the lights are starting to “flow”. It is a really nice optic effect.
The same effect but with LED’s. I have done this one for a friend car. The surprise is that every time you start it, the light flow behaves different.
A very simple example for beginners.
The same simple example, but now for 220V. You can use a simple contact relay, and then you get a flashing light, or you can use a double anti-parallel contact relay and then you get two flashing light. You can use also two rows of light (you have to take a bigger relay or tyristors).
Please take care when you work with high voltage. You have to take in consideration the isolation standard. It is for your own good.
It is getting dark? And you don’t want every evening to get out to turn your garden light on? It can be done in a simply way. A phototransistor measures the out light. If it has a smaller value as the one prescribed with P, the L bulb will light. You can use more then one bulb just by replacing the bulb with a relay or a tyristor.
For audio signal level controlling you can use one of the following applications.
For stereo applications you have to build two of them, possibly identical.
Do you want to speak with your visitors from your room or from your garden? You can do it! You can use audio speakers or normal telephone speakers. You can speak and listen. The speakers must be inverted. There is a simply solution presented with a commutation switch.
That’s an easy tester I’m using to assure that my last application didn’t destroy the computer port. You can use the same thing for disco light programming (Borland Pascal, C++, etc). Just try to use an interface between them. Just in case.