Two-Motor Walker Circuit Designs -------------------------------- by Terry Newton NOTE: These are all versions of the Nervous Network, invented and internationally patented by Mark Tilden. Commercial usage is prohibited unless arrangements are made with the patent holder . None of these circuits have core-monitoring functions, if it locks up it has to be reset manually. A solar-bot should have circuitry to issue start and stop pulses at intervals to prevent discharging the battery all at once, like a bi-core instead of separate one-shots. Not responsible for any errors typos or if it just doesn't work, works for me. These are to document the circuits I am using, in case someone else finds them useful. ____________________________________________________________________________ Basic Microcore walker circuit... .-----o---------o--------------------------o---------o----< + _|_ | 1N914 | | 4.7u | | | __|__ | __|__ | |22 | / \ | 74HCT14 by 5 sections _____ | |Meg| /___\ _ | (ground unused input) | |20 74HCT245 |_ _| | | -_| _|_ ___|___ | | | -_ 19| |1 'A' o-----o-----| _O-----o------------------------| |----. | | | _- | | | _|_ | O __|__ |_- | __|__ 18| |2 |-| _____ | \ / 1N914 .--|---R---|--. | O | .2u | _\_/_ |17| |3 | Motors _|_ _|_ _|_ | .-------o--| |--o-----. reset | | 16| |4 | switch .---------------o 'B' | .--|---R---|--. |+ (optional) | | |15| |5 | Rear .----------- | ------------------------------------o--| |--o--. |- | | | 14| |6 | | | | .----------------' .--|---R---|--o-----' | | | |13| |7 | |- | | | .---------------------o--| |--' Front | .2u | _ | | _ 12| |8 |+ | | | -_ | | .2u | -_ .--|---R---|--o--' | | | | | -_ | | | | | -_ |11| |9 | | .---| |--o---| _O--o-----| |--o---| _O---o--| |--' | | | | | | _- | | | | | _- | |_______| | _|_ _|_ |_- | _|_ |_- | |10 | | | | | | | | | | | |10K| |1.5| | |1.5| | _|_ | | | |Meg| | |Meg| | | |_ _| |_ _| | |_ _| | R = optional load | | | | | | resistors (1K typ) | | _|_ | _|_ | `---o | | | _ .2u | _ .2u | | _- | | _- | | | _- | | | | _- | | | | `----O_ |---o--| |----o---O_ |---o--| |--' -_ | | | | -_ | | | | -_| _|_ -_| _|_ | | | | |1.5| |1.5| Optional status LEDs |Meg| |Meg| and resistors not shown |_ _| |_ _| Connect +-LED-2.2K-outs | | _|_ _|_ [Additional power up/down circuit deleted - didn't work well enough and there are better uses for the extra gate, like a stop switch] _______________________________________________________________________ Another walker design (one that actually got made)... .----.--- + _|_ | 2.2u |1.5| _|_ .---||------.-- + |_M_| /_\ 914 | _|_ | | |\ 914 914 /| | 914 |390| :----:-----| >O--|>|-. .--|>|---O< |---:----.--. |___| _|_ _|_ |/ | | \| _|_ _|_ | | |10 | ___ 2.2u | | |1.5| /_\ | O|_ Stop |___| _|_ | '--------. |_M_| | | O| Switch | /| | | _|_ _|_ '---' _|O .--< |-------------------. | |O | *\| .1u | |\ | .1u | |\ |\ _|_ | .--||--1---| >O-'--||--2-----| >O--.-----| >--. Start | _|_ _|_ |/ _|_ | |/ | |/* | Switch | |2.2| |1.5| |1.5| | | | | |_K_| |_M_| |_M_| | | | + | _|_ _|_ | | + Rear | | | Front Motor | | | Motor - | .------------------------------' - | \ / | | | \ '--. | | / \ | |\ | | | `----------------------------.-------| >--' | /| | | | |/* '--< |-- | --------------. | '------. *\| | .1u |\ | .----. .1u | |\ | '--||--3---| >O-'-|2.2K|--||--4---| >O--' + = 3.6 volts _|_ |/ '----' _|_ |/ (phone battery) |1.5| |1.5| |_M_| |_M_| 2.2u from + to gnd _|_ _|_ .....(*) each motor driver....... Offset adjust... : : + : .-- + : _|_ : b |/ c : | | .----. : .-------| : |___|<--|10M |--> in #1 : | npn |\ e : _|_ '----' : | .----. | : : net ----:-|470 |--:---- motor : + (or to the inputs : | '----' | : _|_ that need trimming) : | b |/ e : | | .----. : '-------| : |___|<--|10M |--> in #4 : pnp |\ c : _|_ '----' : _|_ : : : Trims optional, could simply add :...............................: high value resistors as needed As it turned out, the '245 of the original circuit didn't have enough current drive to power the 3v gearhead motors I got from Marlin and Jones Associates, so I used discreet transistor pairs. Much more drive, and smaller too. The 470 ohm resistors are optional, mine seems to work better with them. The nodes for introducing the start and stop pulses were chosen more-or-less at random. The offset trimmers were connected to the nodes they seemed to work best on. The 2.2K resistors shown in series with two of the caps allow the start and stop reset pulses to work reliably, they prevent the previous node from shorting out the signal. .1uF caps used instead of .2uf to speed it up - small 'bot. (eventually went to .12 uF to slow it down somewhat) _________________________________________________________________ A two-motor walker that can back up... This uses two dual-wire crossers to reconfigure the network so that it can go in reverse. A one-shot activates reverse mode for about 10 seconds when it encounters an obstacle. Increase the 4.7uF cap for more time. + | Npn >|-----. .---|>|--*-- + | .---. | /| | .----. | Reset Sw. .------*-|470|-*--------. .---O< |--*-|1.5M|-' .---O|_ | | `---' | | | \| | `----' | O| | Pnp >|-----' | | 2.2u | .----. | _|_ + | _|_ .---|<|---|-----' .--||--*-| 10 |---' | | | | _|_ `----' .-----|< Npn | .12u |1 |\ | .12u 2 |\ | .---.e| | .--||--*---| >O--*---. .--||--*---| >O---*--*-|470|-*-----. | | _|_ |/ | | _|_ |/ | | `---'e| | | | |1.5| 74HCT14 | | |1.5| | `-----|< Pnp | | | |_M_| | | |_M_| | _|_ | | | _|_ | | _|_ | | | | | `------. | | | | CD4016 by 2 .---|----------|----------' | | | .----------|---|----------|-. | | | .-|-*-|><|---* `-*-|><|---* | + | + | | *-|--' | | `---|-* _|_ + Rear \ / | `-|><|-. | `-|><|-. | | |100| Front Motor \ | `--|-|-*------' | | | |_K_| + Motor - / \ | .-|><|-|-' | .-|><|-|-' | .----. | e| - | | | | | `--|---*---|--' | *-|220K|-*--|< Pnp | | | `-|-*-|><|-* | *-|><|-* | `----' | | | | `----' ` | | | `-|---*------. | | | | .----.`---|---|------|----------|-. | + | | | .-|100K|----*---|------|----------|-|----' | | | | _|_`----' .-----' .----' | | .-----|< Npn | | | .12u 3 |\ | | .12u 4 |\ | | | .---.e| | | `--||--*---| >O--* `--||--*---| >O-|-*--*-|470|-*-----' | _|_ |/ | _|_ |/ | | `---'e| | |1.5| | |1.5| .--' `-----|< Pnp | |_M_| | |_M_| | _|_ | + _|_ | _|_ | .-|>|-. | | | 1 or 3 2 or 4 | _|_ | 4.7u | Npn >|-----. | .-> <-. | *--||--*-- + | |e.---. | | _|_ Offset Trim_|_ | /| | _|_ `------*-|470|-*--------'|10 | + + |10 |`-O< |---*--. |390| |e`---' | |_M_| _|_ _|_ |_M_| \| _|_ | |___| Pnp >|-----' | | || | | |1.5|| | Reverse _|_ 1M `->|_ _||_ _|<-' |_M_|| O|_ Switch trimpots _|_ _|_ (optional) _|_ `---O| \ | | | Circuit notes... --|-- is a crossover, --*-- is a junction, _|_ is ground. | | Triggers are 74HCT14, quad switches CD4016 (4066 should work but had 4016s) Transistors g.p. npn and pnp TO92 type, diodes g.p. 1N914/1N4148 type. Offset trims connected to nodes 1 and 4 on my 'bot, how my tolerences fell Power is 3.6 volts switched (cordless phone battery) with 2.2u cap to gnd + and - left off of electrolytics, if you don't know don't make this... Motors are Marlin P. Jones & Associates #8679-MD Many (most:) of the components were chosen from what was laying around so don't go by my values... change the .1uF/1.5M ratio to adjust speed. The 470 ohm resistors shown between b/e of the motor drivers might be too small for your application - the purpose of these resistors is to transfer some of the motor 'feel' to the microcore. The transistors I'm using had an HFE >100 plus the motors are fairly stiff, lower gain transistors and/or looser motors wouldn't need as much if any feedback. Sensors may be connected to notes 1 to 4 for more personality, here are some ideas I've been experimenting with... / .-----. .----. Feeler / .--|photo|---*---| 47K|---- + | _|_ | cell| | `----' .----. .--->|<--. `-----' `----|>|----|5.6M|-----> .----. | | | `----' To Nodes <--|1.5M|--|>|--*----|---' 1-4 `----' _|_ Different connections give different behaviour patterns, currently I have the photos going to the front nodes (2 and 4) and the feelers to the back (1 and 3) with no cross but this will change I'm sure. Use additional diode/resistor pairs to activate multiple nodes at once. Experiment! The slightly annoying 'feature' of starting up in reverse can be fixed with a transistor and a couple of resistors... .----. .--|100 |---> to backup switch .----. | `----' from reset out >---|4.7K|---|< Npn `----' e| _|_ This walker circuit seems mostly 'solid' but definitely is not the last word or even the 'correct' way to do it. I don't know what that would be. I present these schematics not to copy as-is but to get ideas.