Build Procedures/Section Three - VEMS wiki www.vems.hu

BuildProcedures/SectionThree (2006-03-16 04:43:08)

Additional components for GenBoard/VerThree when bought from WebShop

There is a similar GenBoard/Manual/InitialTesting/VerThree page, what is the strategy??? GenBoard/Manual/InitialTesting/VerThree - Initial testing and wiring tips (General stuff) / VEMS/BuildProcedures/SectionThree - Additional components for GenBoard/VerThree when bought from WebShop (Component specific)

Note that at most places there is a huge range of good values (eg. supply caps' capacitance). V3.1 has basically everything installed (except the FETs and IGBTs) that is needed to run an engine fuel, WBO2 and spark, but you probably want to review what does what. And maybe you want knocksensing, EGT

See

KinderGarden/Components if you are not familier with units (like nF, uF etc...)
GenBoard/VerThree/RescueKit to find out more about the components in your rescue kits received with the board

Power:

Note that this section is according to one's taste. Some leave out the fuse, transient suppression diode, inductor and does not install extra caps. Others just make a small section from a very thin wire as a fuse. Some people install a lot of supply filtering. Unfortunately the high voltage ramp of the ignition switching (unless you put ignition modules close to the coil on plug transformers) emit some electromagnetic radiation from the wires, no matter how well the supply is filtered.

Recommended setup - this is appropriate in many cases, ask from experts (first put on your MembersPage) if you're not sure

External 5A Fuse (in the wiring)
450mA F1 on PCB for mains
See GenBoard/BuildProcedures/Stepper (D45 options)
L3 1.5uH, 5.4A in holes of F1 (big standing black headshrinked barrel, with a 1R5 on it: this part measures appr 0 Ohm with DVM in each direction - or 0 mV with DVM swithced to diode measurement) You can also solder a short to original place of L3
D37 Transient supression diode. U$5 on the PCB, the biggest diode on the board, right to the main supply regulator, see [picture: big black diode mounted on the bottom on this v3.2]; measure 1k5e22 (or 1k5e18) with your DVM, this is a 22V (or 18V) zener, effectively. If you apply bad power (maybe a sometimes misbehaving alternator), the transient suppression diode usually saves the board (if you apply it! the transient diode is shorted afterwards). Will cost a few traces if you don't apply a fuse, or a fuse if you apply one.
C72 10 uF (1210 size, 35V) recommended for best noise reduction. Alternatively 1uF (1206 size, 50V) or as a last chance 1uF (0805 size, 25V).

Only issue before v3.2:

U24 for Hall supply (in rescue kit for v3.0, marked "A E"; onboard v3.1)
D6 on v3.1 you can short the small LM4148 diode feeding the fetdrivers. (it is missing on v3.2 and not really needed at all. We had a report of failure, although it might be related to bad installation with that board).

for serial port' see GenBoard/Manual/CommHardware

Needed for MAP sensor:

R12 10k

C10 100nF - 10k and 100nF RC filter (10k * 100nF = 1 msec)

C11 min: 0,1uF (220nF - 2.2 uF?)

Cextra10 Optional The [MPX4250A datasheet] suggests a small cap on output of MAP - (pin1=MAP_SIGNAL) to +5V (no individual pads, but easy to put a 0805 SMD cap there) there's a huge range of good values though, use 470pF..1nF if you have (but max 100nF). The datasheet says to GND, but doesn't matter for a cap if it goes to VCC or GND. Except at powerup: it's better if it goes to VCC [AN1646 Noise Considerations]

MAP signal (U2-pin1) is often connected to EC18-pin3 when the sensor is not mounted onboard (electronic connection instead of case-mounted pressure-fitting).

Needed for Temp sensors:

The best value for these depend on your actual sensors: 2.2 .. 2.7k are usually OK. Some bias can be corrected with easytherm perfectly. It is a very good idea to check operation anyway, so you better calibrate if you are there.

R9 2,49k for CLT

R10 2,49k for MAT

V3.2, Both of these resistors are soldered when you get the board, 2.7k

Needed for primary and secondary trigger: See

GenBoard/Manual/InputTriggerHardWare

Needed for ExhaustGasTemp: see GenBoard/Manual/ExhaustGasTemp

Needed for acoustic knock sensing:

See GenBoard/Manual/KnockSensor

Needed for IGN:

Ignition IGBT

R22, R40, R41, R42, R64 R96, R122, R123 (these gate resistors are preinstalled)

V3.2, Solder the IGBT's only

NOT Needed for IGN:

D11, D18, D19, D20, D26, D30, D33, D34 (leave open)

Injector section

Check out GenBoard/Manual/DDFlyback

Needed for INJ, DR FlyBack suggested:

FET: FQPF20N06L

D7, D8, D10, D16, D17, D25, D28, D29 (S2J) You want to connect the flyrail to the positive(+) of injectors (no fuse or switch in between!!)

R18, R21, R36, R39, R60, R63, R92, R95 (33 Ohm resistors recommended with FETdrivers; max 1k gate resistors without FETdriver, but no PWMing than)

Check out GenBoard/VerThree/LowZInjectors

U3, U6, U8, U9 (when not using FETdrivers, short pin 2 to pin 7 and pin 4 to pin 5 at every place)

Normally using diodes or short here, NOT resistors, check GenBoard/Manual/DDFlyback

R19, R20, R37, R38, R61, R62, R93, R94 (just short these to 0 ohm)

Q19, C61, D32, R121 (leave them open)

V3.2, Solder the missing flyback diodes, check GenBoard/Manual/DDFlyback and don't forget the wire from flybackrail to EC36

Needed for 1st channel WBO2:

This part should be dropped, because duplicates GenBoard/Installation/WBOconnect

R51 510ohm (Pump1+)

R102 75k (Nernst_Cell1) Do not solder this, if you have only a NarrowBand oxygene sensor!

R133 10k (Heater 1)

R134 1k (Heater 1)

Q18 FET Transistor (Heater 1)

V3.2, Only solder the Q18 FET

Needed for TPS

The variable resistor type TPS sensor needs GND and +5V input so it can emit an output signal between 0..5V (real range is often just 1..3V, but don't worry, it's configurable). The simpler throttle-idle-switch only requires GND, but that is not a real TPS anyway.

populate R142 (270 ohm) and C69 (220 nF) which makes a current-limited supply for your TPS. These (R142 and C69) are not automatically populated on V32 either, since some people uses this EC36 pin for other purposes (eg. input pin) and applies an "offboard R142" in the wiring for the TPS.

Refrain from using the HALL5V signal directly unless absolutely needed (eg. for HALL sensor supply). Especially avoid shorting it to GND (the onboard 78L05 limits to 100mA and it might survive for some time, but it's not guaranteed).

Needed for bipolar stepper motor control

Stepper chip (DIP16) L293NE or SN754410

if you want inductive load on stepper lines (not unlikely, eg. stepper motor is inductive) you want to short the diode D45 (which powers the stepper chip) with 2.5 .. 5A fuse (or with some experience a thin wire ~ poor man's fuse) parallel with a reverse populated D45 (yes! anode on the stepper chip side).

8 x S2.. stepper flyback diodes on the bottom. Only required for L293NE (that is not sold in WebShop for a long time now), not necessary for the common SN754410 as SN754410 has internal clamping. For L293NE make absolutely sure the 8 pieces of S2.. diodes at the bottom side of the stepper driver are soldered in (only possible on v3.0 or v3.1, pads removed from v3.2). If you drive resistive load, these flyback diodes are not needed, since the resistive load will not activate the FlyBack (but the inductive will).

Not Needed:

R5 PEN on AtMega

C49 Fuel Pressure

even the reset circuit (wether RC or MCP809 type) can be dropped (the AVR has internal brown-out protection, and pullup on reset line)

See also