4qd Uni Series User manual
Uni Instructions
“We're in Control”“We're in Control”
Instruction Manual
Uni series controllers
Issue 07
2 Introduction
2 Models
2 Motors
2 Safety
3 Features
3 Specifications
4 Mounting
4 Connections
5 Power Connections
5 Battery wiring
5 Motor wiring
5 Controls
6 Battery Condition Indicator
6 Internal 4 pin connector
7 Adjustments
7 Gain
7 Acceleration ramp
7 Deceleration
7 Braking
7 Reversing
8 Heat & Heatsinking
8 Use as voltage follower.
4QD’s Uni range of 1 quadrant and 2 quadrant speed
controllers are well suited to general purpose speed
control applications. They are used extensively by
hobbyists and industry.
Amongst other applications our controllers have been
successfully used in the following:
Camera dollies
Caravan shifters
Carnival floats
Conveyors
Electric boats
Electric bicycles
Electric wheelbarrows
Factory stores vehicles
Floor cleaning machines
Golf caddies
Kiddie cars
Miniature railways, 3”, 5” and 7¼ gauge
Mountain rescue vehicles
Potter’s wheels
Remote controlled vehicles
Ride on golf buggies
Winches
Window cleaning machines
Wherever battery motor speed control is required.
Date printed: 27th January 2015
Models
2 models are available, for different current ratings. in various versions and with regenerative braking / no
braking option.
12v 24v 36v 48v Current
Uni-4-12 Uni-4-24 Uni-4-36 Uni-4-48 40 Amps
Uni-8-12 Uni-8-24 Uni-8-36 Uni-8-48 80 Amps
Page 2 Uni Instructions
Introduction
4QD’s Uni range are Universal, Uni-directional
motor speed controllers for battery operation
covering the range of currents up to 110 amps
intermittent. Three voltage options are commonly
available: 12v, 24v and 36v. A 48v version is also
available to special order. 4QD can also supply dual
voltage versions which can be changed by shorting
out a resistor.
They are high frequency chopper drivers giving
control of motor speed both in drive mode and
braking mode. They use MOSFETs in state-of-the-
art, high frequency circuitry to give best possible
performance, reliability and battery economy.
Our drives are protected: provided you don’t actually
connect them wrongly or short them out, they will
survive almost any type of motor or misuse.
The Uni case removes easily by unscrewing the two
screws in the cover. You will need to take the cover
off if you wish to adjust the controller’s performance.
Handling
Be warned that the main capacitors in the controller
retain charge for a long time after the battery is
disconnected. Do not therefore allow any metal
object (screwdriver, wire etc) to contact the board
when the cover is off or it may be damaged.
Motors
The Uni is a very robust controller which will work
with almost any brushed motor.
However you should always make sure the motor is
in good condition: old, dirty, worn motors will not be
reliable and can even cause controller failures.
We also suggest you fit a motor suppression
capacitor. A 10n ceramic across the motor brushes, as
close to the motor as possible, can greatly increase
system reliability. Some motors are available with
this capacitor fitted as a manufacturing option
Safety
It is normal practise, on passenger carrying vehicles,
to include some means of disconnecting the battery or
motor in an emergency. This is normally to guard
against a failure in the controller or wiring which
could cause the motor to run at an uncontrollable top
speed. The Uni range controllers are protected so that
such failure is very unlikely but the constructor
should consider what might happen in the event of
such a fault and should consider fitting an emergency
circuit breaker, relay, or battery disconnect switch or
arrange the battery so it can quickly be disconnected
in the unlikely event of a controller failure. All
passenger carrying vehicles should, in any case, be
fitted with a mechanical braking system for
emergency use.
Warning: Never use a battery switch to turn the
controller on with the pot not at zero. This is
especially important on the 36v and 48v versions
where it can cause a resistor (beside the reverse
Polarity protection relay) to overheat. The controller
turns itself on/off automatically as the pot is
advanced/returned to zero
Battery Polarity
The Uni is polarity protected so a battery reversal
will not instantly damage anything. However be
warned that if the battery if left reversed for any
length of time, a resistor in it can be damaged.
Be warned also that connecting any battery wire to
the motor connections could destroy the controller.
Page 3Uni Instructions
Internal Features
Gain adjust
Acceleration (below)
Deceleration (top)
(on daughter board)
Reverse polarity protection relay
Heatsink/mounting block
Battery +
Battery -
Motor -
Motor +
Input connector
top
wiper
Pot min
batty A
B
C
D
Relay resistor
Trickle resistor
B
A
Speed pot input is via a 4 pin connector, supplied.
Power & Motor connections are by means of 6.35 blade connectors, as shown.
Specifications - Uni-8
Supply voltage 12v or 24v or 36v or 48v depends on model.
Supply current 30mA at zero speed
Output voltage 0 to 100% full speed, adjustable
Output current max (typ). 115 amps (100 amps regen)
1 minute rating 85 amps without additional heatsink!
2 minute rating 45 amps without additional heatsink!
continuous 30 amps or more: heatsink dependant
voltage drop at 20a 130mV
Overheat current 25 amps typical
Overheat temperature 95°C on heatsink
Switching frequency 20kHz approximately
Acceleration time 330mSec to 7 Sec (adjustable)
Deceleration time 330mSec to 7 Sec (adjustable)
Input 4k7 to 25k pot or 0-3.5v (adjustable)
3.5v on pot wiper (gain at max) for full speed
Pot fault detect greater than 130% Full Speed approx (if activated)
Size 71mm x 71mm x 35mm plus tags
case 75mm x 75mm x 40mm plus tags
base 80mm x 100mm x 4mm
Weight board version 110 gm
enclosed version 210 gm
Page 4 Uni Instructions
The controller must be mounted suitable housed to
protect it from the weather and from inadvertent
contact with foreign bodies, so the use of the correct
cover is advocated.
The controller mounts via the heatsink as shown in
the diagram, right. Mounting will normally be onto a
metal plate which will act as heatsinking.
Steel is not a good heat conductor -you should use
aluminium or even copper.
Make sure the controller cannot get wet: normally
when mounted as shown and correctly covered water
cannot get onto the circuit board, and water on the
base will do no harm. Make sure water cannot run
down the wires into the controller.
Heatsink mounting holes are tapped M3 and spaced
at 25.4mm (1”).
The integral heatsink is isolated.
Mounting
Connections
The diagram shows the simplest connections needed to use the controller.
More detailed information on wiring follows.
Permanent
magnet
motor
Green or Black - min
Blue - wiper
Red - max
Yellow not used
Max
Min
Red
Red
Black
Yellow
Blue
Page 5Uni Instructions
Wire size.
Use heavy duty wire for the battery, and make them
as short as possible. This also applies to the battery
linking wire on 24v systems. 4mm22wire is generally
adequate.
Use of wire that is too long (and/or too thin) will
cause loss of power and may also cause the
decoupling capacitor (see ‘features’ diagram above)
to heat up. Under extreme conditions the capacitor
can disintegrate. Heat will also shorten the operating
life of this capacitor. Once the capacitor fails the
current output will fall dramatically.
Motor wiring
This is not so critical as battery wiring: too long
and/or too thin wire will cause a loss of maximum
current, will get hot and will waste battery power but
will not damage the controller. However, wire which
is too thick will do no harm either so we recommend
the same wire for the motor as for the battery.
Battery wiring
Battery connections to the controller are shown in the
diagram, left. Use only good quality battery
connectors: a controller with regenerative braking
feeds current back into the battery during braking and
if a battery connector falls off when braking this
regenerated current can pump up the voltage on the
dud battery connection.
Power Connections
Controls
The only external control the UNI needs is a speed
pot, shown in the diagram, below left. There are other
controls that you may add if you wish.
The Uni turns itself off automatically when you turn
the speed to zero, so you can fit an on/off switch in
series with the red wire as shown in the diagram
below, right. Opening this will remove the voltage
from the pot, so the controller will run down to zero
sped and switch off.
With the pot at zero, the controller draws only a very
small current: (24v version, about 1.8 mA and the
12v version about 5,6mA)
The two diagrams below also show the wiring to the
connector (which is internal to the controller) so if
you have the cased version - ignore the connector.
If you aren’t using the yellow wire, make sure it is
arranged so that it cannot touch anything: it carries
the full battery voltage. It is also possible to use these
four wires to connect a battery condition meter.
That’s really all you need to know to get the Uni
working!
Pot fault detection
This feature is not normally engaged: for it to operate
you must fit a resistor as shown in the third diagram.
Use 3K3 with a 10K pot and re-adjust the gain
control. Typically it is enabled to prevent the
controller going to full speed in the event of a broken
wire to the pot.
1
1
Max
Min
1
Max
Min
Max
Min
AA
BB
CC
DD
Green - min Green - min
Red - max Red - max
Blue - wiper Blue - wiper
Green - min
Red - max
Blue - wiper
Page 6 Uni Instructions
A Battery Condition Meter can easily be fitted between pin A of the connector and pin d (green wire to pot) as
shown left, below.
If you want the ignition switch also to
disconnect the pot, then the pot’s max
connection can be connected from the
battery positive, via the ignition switch as
shown far right. In this case you will
certainly need to re-adjust the gain
preset.
Note that a resistor (10K with a 10K pot
but not critical as you adjust the gain
control) should now fitted in the white
wire to the top of the pot.. If this resistor
is not fitted, the pot fault detection circuit
in the controller will not operate properly
and the controller may go to full speed if
the pot or wiring becomes faulty.
When wiring like this, you will have to
adjust the Gain control so that full speed
is reached at full pot rotation.
Battery Condition Indicator
Internal connector
A 4 pin connector is supplied on the circuit board:
bare board controllers are supplied with a mating
connector, shown below.
This is an Insulation Displacement Connector (IDC):
do not strip the insulation from the wires, simply
push them into the top part of the open connector
from the ‘knobbly’ side, and squeeze it closed in a
vice or with suitable parallel action pliers.
The mating connector supplied is suitable only for the
correct size of wire.
Acceptable wire sizes are:
7 stranded 0.22-0.25mm²
Equivalent 24 AWG (7/32 AWG)
As you squeeze the connector closed, the tines of the
contacts bite through the insulation to make contact
with the conductors. Wire which is too thin will not
make contact. Wire which is too thick will damage
the tines.
You can re-open a closed connector by gently
moving the tabs at the sides of the top cover outwards
to disengage the latches while lifting the cover
slightly, one side at a time.
The pin letters show how the pins mate with the
‘features’ diagram.
WhiteWhite
Max
Min
Green - min
Blue - wiper
Red - max Red - not used
Yellow - batt Yellow - batt
Max
Min
Green - min
Blue - wiper
A A
B B
C C
D D
Green
Green
Yellow Yellow
Blue Blue
Red White
1
Closed
D CB A
D
C
B
A
Open
Page 7Uni Instructions
Braking
Regenerative braking is usually a desirable feature
whenever a controller is used from batteries and there
are very few instances where it is disadvantageous.
However for fixed use, from a mains power supply,
braking may prove a problem since, during braking,
energy is returned to the power supply where it can
pump up the power supply to about 36v(for the 24v
version), which could cause failure of some power
supplies.
From Issue 7 boards, it is possible to alter the board
to disable regen braking. Full details are in the
service section of our www site.
http://www.4qd.co.uk/serv/
Reversing
The Uni controllers are non-reversing.
4QD also manufacture reversing controllers such as
the VTX range. These are designed to decelerate and
reverse the motor properly even if the reversing
switch is operated at high speed.
However reversing can be done by a heavy duty
switch or relay.
You will require a double pole changeover switch or
relay to swap the armature connections. The diagram
on the back page shows the wiring.
The normally open contact of one pole connects to
the normally closed contact on the other pole and
vice versa.
Note that motor connects to the moving contacts. If
one pole of the switch jams the moving contacts can
short together which might damage the controller but
will not harm the motor.
Adjustments
There are three adjustments available: Gain,
Acceleration and Deceleration. These are indicated
on the drawing, above.
Important: use an insulated screwdriver when
making adjustments: the metal centres of the
adjustments are 'live' to the internal circuitry. If a
non-insulated screwdriver touches anything other
than a preset the circuit can be damaged.
Gain
Adjust this so that, at maximum required pot rotation,
the controller just reaches full speed. This is easiest to
do with the motor unloaded (i.e. with the wheels
chocked up). Set the speed pot to your required
maximum point then, listening to the motor, adjust
the preset. It is usually quite easy to tell when the
motor stops accelerating and reaches full speed.
If you set the gain control too high, the controller will
probably cut out at full throttle: this is the pot fault
feature which can be implemented fully. See page 5.
As supplied, the controller is set so that it works
properly with a standard 10K pot. You may have to
readjust with, for example, a twist-grip throttle.
For the more technical: The controller feeds
approximately 5.6v to the top of the pot. With the
gain at maximum, full speed is at about 3.5v on the
pot wiper (pin C) and at about 4.5v, pot fault
operates and the controller cuts out.
Acceleration
This adjustment controls the rate at which motor
speed increases if you turn the pot sharply up. Adjust
it to suit your machine.
Deceleration
This adjustment controls the rate at which motor
speed decreases if you turn the pot sharply down.
Adjust it to suit your machine.
If you get these adjustments wrong, little harm will
be done but the machine’s stopping and starting will
either be very jerky because it responds too rapidly,
or it will seem unresponsive as you have to wait for
anything to happen!
IMPORTANT: the switch or relay must not be
operated whilst the motor is running. To do so will
place great stress on the motor and mechanics. To
avoid this, put the reversing switch somewhere so
that it cannot easily be operated from the normal
driving position.
This is the main reason that reversing controllers are
available: they are configured so that reversing is safe
(to the controller) under all conditions, even when the
reversing switch is operated at full speed.
To motor
from Uni
n/c
n/o
n/c
n/o
c/o
c/o
Relay
coil To
battery
Heat & Heatsinking
The rated current output of the controllers is with the
heatsink hot. When cold they will give considerably
more current. Thus the 35 amp version will in fact
give about 50 amps when cold. This is OK because
the MOSFETS used are rated at 60 amps continuous
with a case temperature of 25°C. As the MOSFETs
warm up their allowable current reduces so that at a
case temperature of 100 they can (only!) handle 45
amps continuous. The current limiting used in 4QD’s
controllers senses the MOSFET temperature and
automatically adjusts. However, running the
controllers at full current will cause speedy heating.
However, at some temperature (well above 100°C)
the MOSFETs will become unsafe, so we suggest
that, during initial use, you keep a note of the
heatsink temperature and, if it becomes much too hot
to touch, take appropriate steps, either by mounting
the Uni onto additional heatsinking or, better still, fit
a higher rated drive since heat is wasted battery
power and a larger drive will waste less. When using
an external heatsink remember that steel does not
conduct heat well: aluminium is far better.
For good heat conduction you must also use heatsink
compound between the Uni's on-board heatsink and
any external sink you fit.
Instead of a pot the input may be fed from a variable
voltage. 0v (common) to pin D, signal input (+ve) to
pin C.
Zero speed will be for zero voltage input and full
speed voltage may be adjusted (by the pre-set) to be
from 3v to above 20v.
If the input is a PWM signal, e.g. from a
microprocessor, and its amplitude may be above 5v,
then the pot fault protection circuit needs to be
deactivated. Two resistors are marked A and B on the
features diagram on page 3
To disable Pot fault, either disconnect A, or link out
(short circuit) resistor B.
Use as voltage follower
This manual suits for next models
8
Table of contents
Other 4qd Controllers manuals
