Automatic Running-in Bench, part 1
for internal combustion model engines
Even though brushless electric motors have largely replaced internal combustion engines in small- and medium-sized radio-controlled model aircraft, many model enthusiasts are still attached to internal combustion (i/c) engines and these need to be run in before they can go airborne. This ambitious project automates this important operation.
Materials
Gerber file
CAM/CAD data for the PCB referred to in this article is available as a Gerber file. Elektor GREEN and GOLD members can exclusively download these files for free as part of their membership. Gerber files allow a PCB to be produced on an appropriate device available locally, or through an online PCB manufacturing service.
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Extra info / Update
Technical specifications
- 32-bit ARM7 processor running at 59 MHz, 128 kB flash memory and 64 kB RAM.
- Throttle control by standard model servo. Configurable travel and direction of movement.
- Microcontroller-driven glow plug heating.
- Engine speed measurement from 0 to over 30,000 rpm.
- Engine temperature measurement from 0–160 °C.
- Ambient temperature measurement
- Mixture adjustment managed by the on-board software.
- Mobile pocket terminal with 4-line / 20 character alphanumeric LCD display, push buttons and encoder knob.
- USB link
- Direct Servo Control (DSC) interface
- Emergency stop push button
- Power supply: 7–15 Vdc
March 17, 2009. Corrections
1. Page 31, central column, line before header “Construction”. Text should read:
And lastly, the terminal's LCD backlight is controlled by a P-channel MOS transistor.
2. At the beginning of the paragraph "Testing the pocket terminal (GMMI)", 'JP8' should read 'JP6'.
3. D10 in drawing 080253-14 (main schematic) should be 3V3 , not 5V6.
4. Do not to use a readymade 'type 1' RJ6 cable (crossed wires!) to hook up the pocket terminal to the main board, but a straight 1-on-1 cable. This is also known as '6 pole 6 connector RJ11 plug to plug modular cable, Straight-Reverse' (pin1 to pin1, pin2 to pin2… pin6 to pin6). This cable will be included in the kit for the project.
Component list
Resistors
(0.25W 5%)
R1...R4, R7, R9, R48, R58 = 47kOhm
R5, R6, R26, R32, R33, R45, R47 = 10kOhm
R8, R25, R49, R50...R53 = 2kOhm2
R10, R11, R24, R27 = 220Ohm
R12, R13, R17, R18, R28, R34, R39 = 5kOhm6
R14, R15, R16, R19, R20, R29, R35, R38, R40, R41, R44, R46 = 1kOhm
R21, R22, R23 = 100Ohm
R31 = 39kOhm
R36 = 180Ohm
R37 = 390Ohm
R42 = 1kOhm5
R43 = 22kOhm
(0.25W 1%)
R30 = 90kOhm9
(1W 5%)
R54, R55 = 22Ohm
Capacitors
C1, C8, C14, C18, C21, C25, C28 = 47uF 63V, electrolytic radial, lead pitch 2.54mm
C22, C37 = 470uF 35V, radial electrolytic, lead pitch 5mm (0.2”)
C33 = 220uF 16V, radial electrolytic, lead pitch 2.54mm (0.1”)
C26 = 47uF 10V, tantalum, case C (Kemet: T491C476K010AT)
C2...C7, C9...C13, C15, C16, C17, C19, C20, C23, C24, C27, C29...C32, C34, C35, C36 = 100nF / 50V, ceramic, lead pitch 2.54mm (0.1”)
Semiconductors
D1, D11, D12 = 1N5822, Schottky diode, 3A, 40V
D2, D5, D16, D17, D18, D19 = 3V9, 0.5W, zener diode
D4 = 1V4, 0.5W, zener diode
D6, D7,D8,D9 = 5V6, 0.5W, zener diode
D10 = 3V3, 0.5W, zener diode
D14 = 9V1, 0.5W, zener diode
D3, D15 = LED, red, low current, 3mm (0.12”)
D13 = LED, green, low current, 3mm (0.12”)
IC1 = FT232RL, SSOP28
IC2 = LM3724IM5-3.08, SOT23-5
IC3, IC4 = PCA9517A, SO8
IC5 = LM2940CT-5.0, TO220
IC6 = AD7417ARZ, SO16
IC7 = TLC272, DIP8
IC8 = ULN2804AFWG, SOL18
T1 = IRL3502SPBF, D2PAK
T2, T4, T5 = BC547B, TO92
T3 = BC557A, TO92
Miscellaneous
JP1…JP10, JP12 = 2-way pinheader, lead pitch 2.54mm (0.1”)
JP11, K5 = 3-way pin header, lead pitch 2.54mm (0.1”)
K1, K3 = 2x10-way flat cable socket
K2 = USB type B socket, PCB mounting
K4, K15, K17 = 2-way polarized vertical header, wire-to-board, lead pitch 2.54mm (0.1”) (Farnell # 588570)
K6, K7, K8, K9 = Socket RJ11 6/6, horizontal (Farnell # 9732071)
K10 = 2x5-way flat cable socket
K11, K13 = 2-way side entry male header, PCB plug-in connector, pitch 5.08mm (0.2”), male, soldered connection, 90° (Farnell # 9633197)
2-way female terminal block with screws, free plug, pitch 5.08mm (0.2”) (Farnell # 9633030)
K12 = DC adapter socket, 2.1 mm (0.83”), PCB mounting
K19 = 3-way polarized vertical header, wire-to-board, lead pitch 2.54mm (0.1”) (Farnell # 588581)
K21 = 6-way polarized vertical header, wire-to-board, lead pitch 2.54mm (0.1”) (Farnell # 588611)
K20 = Jack socket 3.5mm (0.14”), mono, PCB (Farnell # 152206)
M1 = P542-M481U-G17L82 (McLennan Servo Supplies), unipolar stepper motor, 2400 steps per revolution (not included in kit of parts)
S1 = push-button, tactile, SPNO
Y1 = Elektor ARMee board mk.II (with LPC2106/01 and 14.7456 MHz crystal)
SK 409/25,4 STS (Fischer Elektronik), heat sink for TO-220/TO-3P, 8.2°K/W (Farnell # 4621293)
IC socket, DIP8
12 jumpers, pitch 2.54mm (0.1”)
2 sockets 1x20-way, lead pitch 2.54mm (0.1”)
1 M3 screw, 10mm (0.4”) to secure heat sink
1 M3 nut to secure heat sink screw
PCB, ref # 080253-1
Outside the PCB:
K14, K16 = 2-way housing, wire-to-board (Farnell # 1098459)
K18 = 3-way housing, wire-to-board (Farnell # 1098438)
K22 = 6-way housing, wire-to-board (Farnell # 1098456)
R56, R57 = KTY81/210 (NXP), temperature sensor, positive temperature coefficient, SOD70 case
Board # 080253-2
Resistors
R1 = 10kOhm, 0.25W, 5%
R2 = 4Ohm7, 1W, 5%
Capacitors
C1, C2, C4 = 100nF / 50V, ceramic, lead pitch 2.54mm (0.1”)
C3 = 47uF / 63V, Electrolytic radial, lead pitch 2.54mm (0.1”)
Miscellaneous
BZ1 = EMX-7T05SP, magnetic transducer, 5V, lead pitch 7.6mm (0.3”) (Farnell # 1193323)
D1, D2, D3 = 5V6, 0.5W, zener diode
IC1 = MCP23017, 16-bit I/O expander with I2C serial interface, DIP28 (Farnell # 1332088)
JP1, JP2, JP3 = 3-way pin header, lead pitch 2.54mm (0.1”)
K1 = RJ11socket 6/6, horizontal (Farnell # 9732071)
LCD1 = LCD Displaytech 204B, 4x20 alphanumeric
P1 = 10kOhm preset, PCB mounting
S1…S4 = 3FTL6 (Multimec), push-button, tactile, SPNO (Farnell # 1132885)
S5 = EC11B15242 (ALPS), rotary encoder, 5V, 15 PPR, panel mount, 11mm (0.44”) (Farnell # 1191733)
T1 = ZMX61P02F (Zetex), MOSFET P, SOT23 (Farnell # 9525297)
3 Jumpers, lead pitch 2.54mm (0.1”)
IC socket, DIP28 narrow
1x16 way socket, lead pitch 2.54mm (0.1”) (LCD connection)
AW 110/16-T (ASSMANN), 1x16 way pinheader, lead pitch 2.54mm (0.1”) (LCD connection)
4 MDLSP1-10M-01 (RICHCO), nylon locking post, height 10mm (0.39”) (Farnell # 1325985)
4 AQC09-24.2 (MULTIMEC), black cap for push-button, height 24.2mm (0.95”) (Farnell # 1132965)
7 self-tapping screw 4x1/4 to secure PCB to case
Case, model BS 800 F-7035 prod nr. 82800135 (BOPLA), light grey; 98x34x209 (WxHxL) [mm] (3.85x1.34x8.23) (WxHxL) [inch]
Black knob, 22mm (0.85”) diameter, 21mm (0.83”) height, 6mm (0.24”) shaft diameter
6-pole RJ11 Male to Male Modular Cable (1m) (3’) to connect 080253-1 to 080253-2
PCB ref. # 080253-2
090146-91 Elektor ARMee board mk.II
LPC2106FBD48/01 (NXP), 32-bit ARM microcontroller; 128 KB ISP/IAP flash with 64 KB RAM, LQFP48
14.7456MHz quartz crystal, HC49/US case, low profile (Farnell # 1538745)
The other components on this board remain unchanged
PCB, Elektor order code 090146-91
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