Simple Millipede Circuit Diagram

Me and a friend are both trying to build a millipede. Because of obvious reasons, the millipede is NOT going to have 1000 feet!!! Instead, it's going to have 16 pager motors as feet. It will also have 3 MicroMotors to ''bend'' towards light, and a backup sensor.

FEATURES:

- 16 PagerMotors as feet
- 3 MicroMotors to seek light
- PhotoTrophic
- Obstacle avoidance
- Looks Cool!!! 

MECHANICS:

Millipede is divided in four segments. Each segment (except the first one) is glued to a MicroMotor turned upside-down. The motor shaft is then glued to the next segment. Each segment can rotate left/right and has 2 PagerMotors on each side. This way, the millipede should turn towards the most lighted area. I've calculated that the waist motors should turn only 30^o-45^o  every second or so. This means that I will need the motors to be 7-15 rpm. Candidates for this job can be the Lego MicroMotor, Solarbotics GM or BabyGM (unless I can get some MU915L Escaps!!!). 

Weigth was a major concern since the whole bot was impulsed by pagermotors.  The waist motors should weigth no more than 70g and the body (including electronics) is about <100g. Actually, it seems that 16 pagermotors are more than enough to move the bot!!!

ELECTRONICS:

I made up this circuit, as this is my first ''big'' BEAM creation I have no idea if it works properly. The upper 3 Ms are the Lego MicroMotors and the lower Ms should be the 16 PagerMotors. On the right, you can see the MicroMotors driver.

 

Here is the explanation:

1	This is the voltage divider. It divides voltage depending on which side is more iluminated, then, the schmitt changes the signal from a wave to a straight pulse.
2	The (usual) Nv only works when the input receives a HIGH, and that is the job of the schmitts. If the first schmitt outputs a HIGH the the lower strip of Nvs will work, the upper strip should stay calm because the second schmitt inverts the signal to a LOW. Thanks Math!!!
3	I can now be sure that there won't be 2 pulses on a same motor, and that when the first motor turns left  (or right) the next one will also turn that same way, and the next and the next.... Only the first motor is affected by light, the others follow (in a wave pattern) the one before themselves. Since the millipede is moving forward while all this happens, a nice wave should appear when the bot has locked his path towards the light source.
4	This is the backup switch. When the bot bumps into something like... Hmm....anything, the cap is discharged trough the right schmitt. The (now LOW) output of the schmitt will reverse the PagerMotors, thus, reversing the whole bot.
5	This is the PagerMotors driver. I took the 4 transistor circuit design and modified it to be used with only one input signal. I know I won't be able to drive the 16 motors with 2N390X transistors, I used them in the schematic only because I need to find more powerful ones. Probably FETs?
6	As an extra (Yupeee), when the bot reverses it also makes the ''spinal column'' think that light is fully comming only from one direction. Because of this, when the millipede reverses, it also turns to one side all the body.

I still need to order the components (Let's just say there are not many 74**14s or 240s in Costa Rica), so the final version may be different than the drawings. I'm also thinking about using the Baby GMs that Solarbotics sell instead of the Lego MicroMotors. If you can help me with anything about the schematic, just email me.

Sourced By: Circuitsstream

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The flashing Heart Circuit Diagram

Buying a gift for someone special or a loved one can sometimes be difficult or expensive. The flashing heart is the answer. It is easy to build and even the inexperienced hobbyist should be able to build it. The estimated cost for the circuit is $25 if all the parts are purchased new. With The Flashing Heart, you can get your message across in bright lights.

Circuit Description

The Circuit Diagram is shown in Figure 1. It consists of a 4047 low-power monostable/astable multivibrator, IC1, used in the astable mode to provide the timing pulses to control the flash rate of the LEDs. To accomplish the astable mode, pins 4, 5, 6, and 14 are connected to +12VDC and pins 7, 8, 9, and 12 are connected to ground. Pins 1 and 3 are connected to C2 and pins 2 and 3 are connected to potentiometer R9. A fixed value resistor can be used in place of the potentiometer R9, if the flash rate does not need to be adjusted. These three pins make up the R-C timing circuit. The output pulses from the 4047 are taken from pins 10, 11, and 13. Pin 10 is the Q output and pin 11 is the Q-not output. These two pins are onnected to R6 and R7 respectively.

Click On Image To Enlarge

The collectors of Q2 and Q3 are connected to R4 and R5 respectively, which are connected to the cathodes of the Yellow LEDs. Pin 13 is the oscillator output and is connected to R8, which is connected to the base of Q1. The collector of Q1 is connected to R3, which is connected to the cathodes of the Red LED's. The emitters of the three transistors are connected to ground. The Green LEDs are connected to R1 and R2, which are connected to +12VDC. Resistors R1-R8 are current limiting resistors and the correct wattage for these resistors should be used to prevent excessive heat. The resistive values may be changed to vary the brightness of the LEDs. The circuit is powered by PS1, a wall transformer, which is connected to a filter capacitor C1. It must be between 10 to 15 VDC and at least 500mA.

Construction

Probably the most difficult part of this project is making the printed circuit board, Figure 2. The board used in the prototype took several hours to make using dry transfers. Using a different technique, such as photo resist, may be faster for the experienced hobbyist. Once the board is etched and drilled, the jumper wires should be placed on the board and soldered, as shown on Figure 3. Next the 84 Yellow LEDs should be placed around the border of the board, followed by the 42 Red LEDs that make up the heart and then the 16 Green LEDs that make up the letters I and U. Resistors R1-R9 and capacitors C1and C2 should be placed on the board next and then the power supply, PS1. Sockets were used in the prototype for the I.C. and transistors. A socket for the I.C. is required, but the sockets for the transistors are not. Special care should be taken when handling the CMOS I.C., as a static discharge will destroy it. When you are finished soldering, check the board over for mistakes. If everything looks okay, apply power.

  

Click On Images To Enlarge

Operation

Once power has been applied to the circuit, the Red LEDs should all be flashing on and off together. The Yellow LEDs should be flashing on and off, but only every other Yellow LED should be on at one time. The Green LEDs will stay on at all times. The flash rate can be adjusted by turning R9. Connections for a fixed value resistor for R9 are provided on the board layout if preferred.To dress up the project, a favorite photograph can be placed in the heart, and a frame can be made to fit the circuit board.

Parts List
Resistors
R1, R2	-	470 ohm, 1/2-watt
R3-R5	-	100 ohm, 3-watt
R6-R8	-	1000 ohm, 1.4-watt
R9	-	5000 ohm potentiometer
Capacitors
C1, C2	-	100uF, 16 volts, electrolytic radial
Semiconductors
IC1	-	4047, low power monostable/astable multivibrator
Q1-Q3	-	2n3643 NPN transistor or equivalent
Diodes
LED1-LED84	-	yellow light-emitting diode
LED85-LED126	-	red light-emitting diode
LED127-LED142	-	green light-emitting diode
Other components
PS1	-	12VDC @ 500mA wall transformer
Miscellaneous: Jumper wire, solder, printed circuit board,
drill and bits,14 pin I.C. socket, and a frame or case.			sourced by : link

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6V Ultra-Bright LED Chaser Circuit Diagram

This is a spectacular but completely useless project. It lights Ultra-Bright LEDs in a sequence and each LED flashes brightly very briefly. The LEDs light-up going around and around since they are mounted in a circle (on a CD), then they pause before chasing again. The very brief flash of each LED (15ms) and the pauses (1 second) reduce the average current so the battery should last a long time.

 

For user convenience, this project has a stepper speed control and a brightness control. At slower speeds and/or reduced brightness, the battery’s life is extended considerably.

At full brightness, the LEDs flash extremely brightly. More than one of this project grouped together occasionally synchronize, lighting the whole room for a moment.

Operation

At maximum speed, the LEDs don’t appear to flash, instead they appear to move from one lighted one to the next, around and around. They rotate completely for 4 rotations in two seconds, and then turn off for a one second pause then repeat the sequence. At a lower speed, the number of rotations before the pause is less. It will do three rotations, two or even only one rotation at its slowest speed. A sequence of rotations starts with LED #2 and end with LED #9. 

6V Ultra-Bright LED Chaser Circuit Diagram

 

Specifications

Battery: Four AA alkaline cells.
Battery life:
                        Minimum speed and brightness              2.3 years
                        Medium speed and brightness                 1 year
                        Minimum speed, maximum brightness   4.1 months
                        Maximum speed and brightness              3.8 weeks

Brightness: controlled with Pulse width Modulation, from off to extremely bright (4000mcd).
Stepper speed: 2 LEDs/sec to 2 revolutions/sec.
Pulse Width Modulation frequency: 3.9KHz.
LED current: 24mA pulses.
LED voltage drop: 3.2V at 24mA. Blue, green and white Ultra-Bright LEDs are suitable.
Minimum battery voltage:
                         <3V, oscillators do not run.
                         3V, LEDs are very dim.
                         4V, LEDs reach almost full brightness.
Radio interference: none.

 

Circuit Description

• The CD74HC4017N high-speed Cmos IC is rated for a maximum supply voltage of 7V. It is rated for a maximum continuous output current of 25mA. In this project, the maximum supply voltage is 6.4V with brand new battery cells and the 24mA output current is so brief that the IC runs cool.
• The MC14584BCP* IC (Motorola) is an ordinary “4XXX series” 3V to 18V Cmos IC, with a very low operating current and low output current. Its extremely high input resistance allows this project to use high value resistors for its timers and oscillators, for low supply current. Its 6 inverters are Schmitt triggers for simple oscillators and very quick switching.
• IC2 is a 10 stage Johnson counter/decoder. On the rising edge of each clock pulse its outputs step one-at-a-time in sequence. It drives the anode of each conducting LED toward the positive supply.
• IC1 pins 1 and 2 is a Schmitt trigger oscillator with C3 and C4 paralleled for a very low frequency. R1 and R2 control its frequency and the diodes with R3 combine with the capacitors to produce the 15mS on time for the LEDs.
• IC1 pins 5 and 6 is the brightness Pulse Width Modulation oscillator. The pot R7 with the associated diodes and resistors allow it to change the duty-cycle of its output for PWM brightness control. It drives the transistor.
• IC1 pins 3 and 4 is an inverter. It takes the low time (LEDs off) from the clock oscillator, inverts it to a high and shuts-off the brightness oscillator through diode D6.
• IC1 pins 11 and 10 is a sample-and-hold stage. It takes a sample of the pulse driving LED #9 though D3 and R4 and charges C5 in steps. At maximum speed it takes 4 steps for C5 to charge to the Schmitt switching threshold voltage. R5 and D5 slowly discharge C5 for the pause time.
• IC1 pins 13 and 12 is an inverter that resets the counter/decoder and shuts-off the clock oscillator through D4, during the pause time.
• IC1 pins 9 and 8 is not used and is shut-off by grounding its input.
• T1 is the PWM switching transistor. R9 limits the maximum LED current to 24mA.

Construction

The 10 LEDs mount on a Compact-Disc which is glued to a plastic box with contact cement. The box houses the Veroboard circuit in its lower main part with the battery holders on its lid. Multiconductor ribbon cable joins the LEDs to the circuit. The pots mount on the sides of the box.

If you turn it down each night, its current is so low an on-off switch isn’t needed.

Parts List

1 IC1 MC14584BCP (Motorola) * Ordinary Cmos hex Schmitt trigger inverters
1 IC2 CD74HC4017N High-speed Cmos decade counter/decoder
1 T1 2N3904 or 2N4401 NPN transistor
8 D1 to D8 1N4148 or 1N914 Diodes
10 LEDs Blue, green or white Ultra-Bright LEDs with Vf = 3.2V or less at 20mA
1 R1 100K 1/4W resistor
1 R2 1M Linear-taper potentiometer
1 R3 33K 1/4W resistor
1 R4 2.2M 1/4W resistor
1 R5 22M 1/4W resistor
1 R6 47K 1/4W resistor
1 R7 1M Audio-taper (logarithmic) potentiometer
1 R8 1.8K 1/4W resistor
1 R9 68 ohms 1/4W resistor

1 C1 100uF/16V Electrolytic capacitor
1 C2 0.1uF/50V Ceramic capacitor
2 C4 and C4 1uF/63V Metalized poly capacitor
1 C5 470nF Metalized poly capacitor
2 C6 and C7 1nF Metalized poly capacitor
 

* A CD74C14 can also be used for IC1 but R4 = 1M, R5 = 10M, C3 and C5 = 330nF, C4 = 470nF.

A 3V LED Chaser project also works well with these changed parts but using a CD74HC14N for IC1.
In addition to these changes, R8 = 680 ohms and R9 = 22 ohms. I built one using low-voltage (1.8V at 20mA) orange Ultra-Bright LEDs. The orange one looks good beside the green one.

Attachments: 6V LED Ultra-Bright Chaser schematic, Veroboard layout and 3 pictures.

I wish I knew how to take a slow picture with my son’s digital camera, so all the LEDs would be lighted, and if I moved it would make nice lighted smears in the picture.
 

Photos

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