Siren on a firetruck
Sirens are built in many ways. The tones and breaks and pitches are all defined by timing and tapering circuits that create a unique or simulated siren sound. A siren is a common build for beginners in electronic development. There are several kits available that will supply a person with all the necessary parts. Many size and sound variations can be gained after familiarity with the basic simple model is acquired. Gain experience by building the unit and researching available plans online or from electronic guides or resellers. With a little preparation and research, a person can make a very functional police siren.
Instructions
1. Situate the PC card. This PC card should have five pad connection areas. These should be placed so that they are at the bottom of the card.
2. Solder the 47 microfarad (uF) capacitor's positive end to the PC board onto the brass that will link to the 47K capacitor. Observe the polarity, and be sure the negative and positive sides are connected to the right points. Solder the negative end to the far brass piece that holds the five spot on the button pads.
3. Solder the 47K capacitor's positive end to the middle node of the brass piece to which the positive end of the 47uF capacitor attaches. Then solder the negative end to the upper node on the 4 place on the pad area.
4. Solder the .02 uF disc capacitor to the two brass node not being used along the top. There are three brass nodes along the top.
5. Solder the second 47K capacitor to the end of the brass strip with the other 47K capacitor and the second node in the first brass strip on the left side of the PC board.
6. Solder the PNP, black side down, across the three points in the middle of the PC board. This will connect buttons 2 and 3 and the NPN.
7. Solder the NPN transistor to the far center points that link button 1, the upper left brass strip and the PNP. Position the flat side of the NPN down.
8. Wire the completed board at pad points 1 and 2, the first two points from the left. Attach the push button to point 3 and 4 to the right of 1 and 2. Wire and connect the positive end of the 9 volt or 12 volt battery to the 3 spot, which is in the center, and the ground to the 5 spot of the pad area, which is the last node on the right.
9. Depress the button to hear the siren.
Tags: brass strip, brass piece, capacitor brass, capacitor positive, side down, that will