will enable the component to operate at its continuous power rating. Thermal grease (e.g. Dow
Corning DC340) should be used and the heatsink should have a surface finish of <6.3μm with flatness of <0.05mm. The resistor should be mounted
using an appropriate bolt as listed in the table below. This should be tightened so as to bring the whole area of the steel substrate into intimate
contact with the heatsink. The unmounted part is slightly bowed so that the centre is above the edges. Inadequate tightening will leave the centre
out of contact with the heatsink, whilst over tightening can cause the edges to rise. The tightening torque required will depend on the fixings and
heatsink used, but typical figures are given for guidance. WDBR resistors will fail safe (open circuit) under overload fault conditions and still maintain
a 1kV dielectric withstand.
Bolt Size
WDBR1/2
WDBR1
WDBR2
WDBR3
WDBR5
WDBR7
M2
M3
M5
M5
M5
M5
Typical Tightening Torque (Nm)
0.6
2
2.5
2.5
3.5
4
WDBR resistors may be customised in various ways including:
Alternative shapes and dimensions up to 406mm x 406mm
Integration of temperature measurement elements
Alternative ohmic values, tolerance & TCR
Increased dielectric withstand voltage
Custom braking resistors with UL approval
For a full Applications Note for dynamic braking see http://www.welwyn-tt.com/pdf/application_notes/WDBR.pdf
·
·
·
·
·
Overload Conditions
Maximum Single Overload Power
100
Power (kW)
Single Overload Energy Capacity
100
Energy (kJ)
10
1
0.1
0.01
0.01
WDBR7
WDBR5
WDBR3
WDBR2
WDBR1
WDBR1/2
10
1
0.1
0.01
W
DB
R
7
W
DB
R
5
W
DB
R
3
W
DB
R
2
W
DBR1
W
DBR1/2
W
0.1
1
10
100
0.1
1
10
100
Duration of Overload (s)
Duration of Overload (s)
Maximum peak current (A)
Value
(ohms)
WDBR1/2
WDBR1
WDBR2
WDBR3
WDBR5
WDBR7
12
15.2
21.6
20.3
25.4
25.4
44.5
15
15.2
21.6
20.3
25.4
25.4
44.5
20
7.6
21.6
7.6
25.4
25.4
44.5
22
7.6
8.3
7.6
25.4
25.4
44.5
25
7.6
8.3
7.6
11.4
25.4
44.5
47
7.6
8.3
7.6
11.4
10.2
20.3
50
7.6
8.3
7.6
11.4
10.2
20.3
100
7.6
8.3
7.6
11.4
10.2
20.3
8.3
7.6
11.4
10.2
20.3
150
General Note
TT electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT electronics’ own data and is considered accurate at time of going to print.
I am a beginner, I know nothing about DSP, I only know some superficial knowledge about single chip microcomputer, but in order to understand 320F2407, I have to learn a little bit, I want Chinese inf...
[align=left][size=4][color=black]Learn AM335X course, draw mysterious gifts activity is in full swing! Thank you for your support and participation. [/color]:congratulate: [/size][/align][align=left][...
The manual of TPS5405 has a circuit diagram but no component model number. Why is that? When encountering this type of chip, how should I know the corresponding component model?...
As the title says: When I open a web page in Windows 6, if there is an input box on the web page, the system will automatically pop up an input panel (soft keyboard). I don't want this thing to pop up...
Microchip's PIC18F46J50 is a low-power, high-performance 8-bit USB microcontroller (MCU) using nanoWatt XLP technology. The current in deep sleep mode can be as low as 13nA, the operating voltage i...[Details]
1. Overview
Will passive devices
produce nonlinear intermodulation distortion? The answer is yes! Although there is no systematic theoretical analysis, it has been found in engineerin...[Details]
0 Introduction
With the development of my country's economy, the number of motor vehicles continues to increase. The growth of existing roads and other hardware facilities can no longer meet t...[Details]
Introduction
Power subsystems are becoming more and more integrated into the overall system. Power systems have moved from being separate "essential dangerous devices" to being monitorable...[Details]
Two simple circuits are implemented to drive two LEDs from a battery powered microprocessor.
This design is based on a circuit that uses three resistors and a microprocessor I/O pin as an input h...[Details]
Instrument stepper motor
The stepper motor is an open-loop control element that converts electrical pulse signals into angular displacement or linear displacement. In the case of non...[Details]
Microcalorimetry
is used to determine energy relationships. Microcalorimetry techniques are often required when performing calorimetric experiments with small sample sizes or slow heating rat...[Details]
I. Introduction
Since RS232 has a short communication distance (only 15 meters according to EAT/TAI-232 standard), and can only perform point-to-point communication, it cannot directly f...[Details]
LED lamps and bulbs are now rapidly replacing incandescent, halogen and CFL (compact fluorescent lamp) light sources in many general lighting applications. Flyback DC/DC converters are the power su...[Details]
Digital array radar (DAR) uses digital beam forming (DBF) in both receiving and transmitting modes to achieve flexible distribution and reception of RF signal power in the airspace, obtain excellent t...[Details]
VP2188 is a color STN LCD module produced by Jingdian Pengyuan. This module is a dot matrix transmissive color STN display screen with a color scale of 65 k colors and white LED backlight. Its core...[Details]
The concept of state machine
State machine is an important concept in software programming. More important than this concept is its flexible application. In a clear and efficient program, ther...[Details]
TC9012F is a universal CMOS large-scale integrated circuit for infrared remote control signal transmission, suitable for remote control of TV, VTR, laser player and other equipment. In the market, ...[Details]
Investment in
the
medical device
industry has been on the rise in recent years. In the past two years, venture capital for medical devices has almost doubled, reaching $4 billion in 2007. Fr...[Details]
1. Disadvantages of choosing too high a voltage level
Choosing too high a voltage level will result in too high an investment and a long payback period. As the voltage level increases, the...[Details]
DSP and ARM Processors
京公网安备 11010802033920号
EEWORLD
