Toy Ambulance Vans

This instructable is about a simple toy ambulance vans that show blinking LEDs and make beeping sounds. Each toy ambulance van circuit is made with a 3 V power source (two AA batteries connected in series) connected in series with a blinking LED and a 3 V buzzer.

The blinking LED turns ON and OFF by itself. Because this LED is connected in series with the buzzer, the blinking LED turns the buzzer ON and OFF.

You can see the circuit working in the videos.

Each toy van needs: buzzer that can work at 3 V, blinking LED - 2 (you might need spare), AA batteries - 2, Dual AA battery holder with a switch - 1, toy wheels - 5 (you might need spare), small gift box, 1.5 mm metal wire, insulated wire (15 cm), electrical tape, masking tape, solder.

Tools: soldering iron, wire stripper, scissors, screwdriver, and pliers.

I drew the circuit with Circuit Lab online software. The design of the circuit is very simple. A blinking LED (light-emitting diode) connected in series with a buzzer to a 3 V power source (two AA batteries connected in series). The second diode (D2) is used to prevent discharging buzzer currents from damaging the LED, limiting the voltage across the buzzer to -0.7 V.

I soldered the buzzer to the blinking LED and connected the power source. I also attached the second diode..

You can see in the video the circuit being tested.

I used screw screwdriver to make holes for the wheel rods and the LED. I widened the hole for the LED with scissors. I used pliers to bend the wire near the wheels so that the wheels would not fall OFF.

You can also attach a geared motor (with a wheel) and make the van move by itself.