The DNO is a popular mid-sized motor control with built-in reversing suitable for use in 12V to 36V applications. The key features are:
- 12V, 24V, and 36V operation easily selectable by internal link [default is 24V]. 48V operation is possible, see notes in specification tab.
- Built-in heavy duty reversing relays.
- Integral box and heatsink [suitable for most applications].
- Timed over load trip [controller switches off if high current is sustained].
- Reverse battery protection.
- Gain control to adjust top speed.
- Adjustable acceleration and deceleration ramps.
- Selectable half speed reverse.
- Selectable dual ramp reverse switching for a smooth transition from forward to reverse.
- DNO-005 Peak current 50A. 1 minute current 40A. Continuous current 30A.
- DNO-010 Peak current 100A. 1 minute current 75A. Continuous current 60A.
- Expansion connector for double-heading locomotives.
- Parking brake driver for vehicle applications.
- Regenerative braking.
- Input 4k7 ohm to 20k ohm potentiometer, direct voltage control, or PWM control by Pi or Arduino etc.
- Direct replacement for the VTX range, uses existing wiring.
The manual provides full instructions on setting up and operating the controller. The manual is available in PDF format:
The manual is designed to be printed double-sided in A4 booklet format. To print the booklet from the PDF on a double-sided printer, select Booklet in the Page Size & Handling section of the print window, and set Orientation to Portrait.
Wiring diagrams and Instructions
Full instructions are included in the manual. The wiring is exactly the same as for the older VTX (except for the expansion connector). Our knowledge base has several alternative wiring schemes.
For troubleshooting common to all controllers click here.
Specific issues you might hit with the DNOs are:
As standard the DNO was designed to block transition from ahead to reverse without reducing the throttle to zero. A number of customers asked if it was possible to remove this block so that the behaviour matches that of the VTX, this can be achieved by the addition of a single capacitor as shown in this modification sheet. The change was incorporated in all DNOs from serial number 16300 onwards.
The absolute maximum voltage of the DNO is 56V which is the same as a 48V battery that has just been fully charged. Above this voltage the internal protection circuits operate, this means that although the DNO can be used on 48V there may be no regenerative braking available. Also the motor may creep and the speed may not be able to be turned to zero.
Under voltage protection
Although the DNO does not have a low voltage protection cut-off fitted as standard it is easy to retro-fit this feature. The fuse link F1 [page 4 of the manual] needs to be cut and a 500mW zener diode fitted between the 2 adjacent holes. The zener voltage Vz is given by Vz = Vco -4 where Vco is the desired cut-off voltage. For example toi achieve a 40V cut off fit a 36V zener diode. The bar of the diode should be to the right hand side as seen on page 4.
Depending on the application some thought should be given to heat dissipation, some options are;
- Making sure that there is a good flow of air over the standard heatsink, either by siting the heatsink in the vehicle airflow, or fitting a small fan.
- Bolting the standard heatsink to a metal part of the vehicle chassis.
- Fitting an aftermarket heatsink to suit your application.
Notes on Current
- The motor current can be a lot higher than the battery current, however the motor power will be equal to the battery power.
- At half speed motor current can be twice the battery current, at full speed motor current is nearly equal the battery current.
- In practise the current limits can be higher than quoted but do not allow the battery current to exceed 100A otherwise circuit board damage may occur.
- The maximum continuous current for the DNO-10 is the rating of the relays and is fairly conservative. It will also depend on how the controller is mounted, heat can build up in the heatsink and, at high currents, must be removed.
We have a number of DNO specific articles in our knowledgebase.
You may need some or all of the following
- A throttle mechanism to control the motor speed.
- Switches e.g. for ignition and maybe reverse.
- Control cable to connect the switches and throttle to the controller.
- Power lead sets to connect the controller to the battery and motor.
- Interfaces e.g. for radio control.
- Relay board to control lights and horns etc.
- Battery meter.