Innovative rotary speed sensors for rail vehicles
Metro Magazine
Incremental Rotary Pulse Encoder Gel 293
Incremental Encoder Gel 293
Incremental Encoder Gel 293
General Information
Incremental rotary pulse encoders convert rotations into electric signals. Lenord + Bauer Incremental rotary pulse encoders combine the advantages of a magnetic measuring system and a robust mechanic design. They have proven successful all over the world in many different applications and even under roughest industrial conditions. Their high reliability and a long service life go without saying.
Fields of Application
- Up to 10,000 pulses per revolution (40,000 with external four-edge evaluation)
- Additionally current output 0 ... 20 mA, 4 ... 20 mA, -20 ... + 20 mA (option)
- Reference signal
- High electromagnetic compatibility (EMC)
Further Outstanding Features
- A hollow shaft for 16-mm shafts
- A coupling is integrated which is highly elastic and offers torsional rigidity
- Extremely high angular acceleration
- IP 66
Measuring Principle
The incremental encoders work with differential sensors depending on magnetic fields and a precision toothed wheel as measure. The sensors scan the tooth structure of the toothed wheel and emit a sine or cosine voltage. The integrated evaluation electronics in ASIC and SMD technology converts the analogue sensor signals into incremental output signals.
Advantages of the magnetic System
- No adverse effect due to condensed water
- Absolute operational reliability even in case of high humidity (dewing) and frequent change of ambient temperature
- Extremely insensitive to dirt, oil and water
- Extremely shock- and vibration-resistant because the measure is not made of glass nor plastic
- Outstanding operational safety over a very long period of time as it does not suffer from ageing effects as optical systems do
Output Signals
Signal pattern V, VN
Signal pattern "V" stands for two tracks with square-wave signals, offset by 90° (push-pull output). With each revolution, a reference signal with defined length is put out on the third track N (optionally). At an output frequency of 200 kHz the edge distance (F) is ≥ 0.6 µs.
Signal pattern T, TN, U, UN, X, XN
Both tracks and the reference signal (option) are additionally output as inverse signals.
Signal pattern S, SN
Pulses which are independent of the rotational direction and the duration of which is constant are derived from the square-wave signals as per signal pattern V and put out on track 2. Furthermore, a signal depending on the rotational direction is obtained from the signal pattern which is put on track 1. Once per each revolution a reference signal is output on the third track N (optional). The outputs have a final push-pull power stage. All outputs are sustained short-circuit-proof. The pulses follow a possible change of rotation with a slight delay, in order that a subsequent counter setting can be adjusted to the counting direction prior to the pulse. The sense-dependent signal may be reversed via a which is accessible from outside (switch 1).
Key
UB = operating voltage
US = signal voltage
a = 360° electrical
b = 90° phase shift
F = edge distance (for an output frequency of 200 kHz the edge distance is F > 0.6 µ)
Signal pattern = shown for clockwise rotation (view on top of the encoder shaft)
Reference signals with other lengths upon request.
Output level
The signal patterns V, VN, X and XN have HTL level, the signal patterns T, TN, U and UN have TTL level (for the output voltage see electrical data).
All outputs have a push-pull power amplifier and are short-circuit-proof. The peak output current for recharging the cable capacity is 100 mA.
Current Outputs
Various Current Outputs
Current Output A: Measuring current which is independent on the sense of rotation and which has a nominal range of -20 ... +20 mA.
Current Output B: Measuring current which is independent of the sense of rotation and which has a nominal range of 0 ... +20 mA.
Current Output C: Measuring current which is independent of the sense of rotation and which has a nominal range of +4 ... +20 mA.
Current output
For displaying and controlling a standardized measuring current of 0 ... 20 mA, 4 ... 20 mA or -20 ... +20 mA which depends on the speed and sometimes on the sense of rotation can be obtained from the pulse frequency. For this purpose the pulse frequency is integrated and converted into an applied current. This results in a strictly linear interrelation between the measuring current and the pulse frequency. Because of the high resolution (up to 40,000 pulses per revolution, each pulse being dependent on the sense of rotation) a standard measuring current with a low harmonic content is obtained at a very low speed range (e.g. 0 ... 0.5 min-1) already. The harmonic content of the output DC depends on the pulse frequency as well as on the chosen attenuation, latter influencing the rise, fall and delay time in case of the speed changing erratically. Attenuation may be specified when odering corresponding to the above diagram, d3 is the default setting.
Data Table of the current outputs
| max. apparent ohmic resistance | Ra | 550 | Ω |
| measuring device class | K | 1 | |
| rated current tolerance | < 1 | % | |
| linearity error | < 1 | % | |
| repeatability | r | 100 | % |
| temperature drift | ΔIaT | < ±.3 | µA/1 °K |
| min. RPM | nmin electrical (attenuation d5) | 1.5 x 103/i | RPM |
| max. RPM | nmaxelectrical | 6 x 106/i | RPM |
i = rated pulse number
Technical data according to DIN 32878
| Description | Gel 293 |
| measuring step from ... to 1) | 9 ... 0.087° |
| pulse number per revolution 1) | 40 ... 40,000 number of pulses |
| Accuracy | |
| error limit 2) | 0.07° |
| incremental deviation 2) | 0.01° |
| repeatability 2) | 0.005° |
| Electrical Data | |
| power RL = ∞, UB = 10…30 V DC
consumption RL = ∞, UB = 5 V DC |
|
| ≤ 1.3 W (with current output: ≤ 1.65) ≤ 1.0 W (with current output: ≤ 1.40) |
|
| output frequency | 0 ... 200 kHz |
| output level for signal pattern T/TN (logic level TTL) |
high signal: ≥ UB - 1.00 V at I = 10 mA; ≥ UB - 1.20 V at I = 30 mA low signal: ≤ 0.75 V at I = 10 mA; ≤ 1.00 V at I = 30 mA |
| output level for signal pattern U/UN (logic level TTL) |
high signal: ≥ 4.00 V at I = 10 mA; ≥ 3.85 V at I = 30 mA low signal: ≤ 0.75 V at I = 10 mA; ≤ 1.00 V at I = 30 mA |
| output level for signal pattern S/SN, V/VN and X/XN (logic level HTL) |
high signal: ≥ UB - 1.80 V at I = 10 mA; ≥ UB - 2.20 V at I = 30 mA low signal: ≤ 1.15 V at I = 10 mA; ≤ 1.55 V at I = 30 mA |
| Mechanical Data | |
| weight | approx. 0.7 kg |
| max. operating r. p. m. | 8,000 |
| moment of inertia of rotor | 8 x 10-5 kgm2 |
| max. acceleration | 5 x 10-5 rad / s2 |
| operating torque | 0.01 Nm |
| starting torque | 0.015 Nm |
| permissible shaft load | ± 1 mm axial 3), ± 0.5 mm radial |
| bearing life | >15,000 x 106 revolution |
| Environmental Conditions | |
| operating temperature | 0 ... + 70 °C (standard); - 20 ... +85 °C (option) |
| ambient temperature | - 20 ... + 85 °C |
| storage temperature | -40 ... +105 °C |
| protection class according to DIN EN 60529 | IP 66 |
| dust and spray protection with O-ring at the flange side (except for the shaft duct) |
same tightness as driving unit, max. IP 66 |
| vibration protection (option) according to DIN EN 60068-2-6 |
frequency 10 ... 2,000 Hz; peak acceleration 100 m/s2; frequency cycles 10 |
| shock protection (option) according to DIN EN 60068-2-27 |
peak acceleration 1,000 m/s2; duration 11 ms |
| insulation strength according to VDE 0660 part 500 version 08/00 or DIN EN 60439-1 |
Ri > 1MΩ, at a testing voltage of 500 V AC |
| electromagnetic compatibility electromagnetic emmissions EN 61000-6-3 electromagnetic immunity EN 61000-6-2 |
The encoders are in strict conformity with Directive EMC 89/336/EEC of the European Union and are therefore certified by the CE mark. |
2) value fo highest resolutions. Values for low resolutions on request.
3) recommended value for minimum pre-tension of the hollow-shaft 1.5 mm
Pin layout: connector, cable
Maximum Cable Lengths
between encoder and secondary electronics. The cable screening is to be earthed one-sided at the receiver. The stated data are standard values referring to cable type LiYCY 6 (10) x 0.25 mm2.
| signal pattern SN, VN, level HTL (UB= 20 V) | ||||||
| f [kHz] | 5 | 10 | 20 | 50 | 100 | 200 |
| Lmax [m] | 200 | 200 | 200 | 80 | 40 | 20 |
| signal pattern TN, UN, level TTL | ||||||
| f [kHz] | 5 | 10 | 20 | 50 | 100 | 200 |
| Lmax[m] | 200 | 200 | 200 | 200 | 145 | 72 |
| signal pattern X, XN, level HTL (UB = 20 V) | ||||||
| f [kHz] | 5 | 10 | 20 | 50 | 100 | 200 |
| Lmax [m] | 200 | 200 | 100 | 40 | 20 | 10 |
Hollow-Shaft Incremental Encoder GEL 293
Hollow-Shaft Incremental Encoder GEL 293
Protection of the electronics (optional)
Protection against humidity
The encoders’ electronic unit is coated with a highly effective protection against humidity, salt-water atmosphere and corrosive vapours to ensure their proper functioning during years even under roughest conditions. Condensed-water outlet
Water may accumulate in the encoder if it is exposed to multiple dewing. The water can drain off through the condensed-water outlet. When mounting the encoder the outlet must show downward. The protection class drops to IP 64. Protection against vibration
The additional fixing of mechanical parts with special plastic prevents the electronics and the connections inside the encoder from vibrating. Thus the proper and continuous operation of the encoder - even if exposed to extreme vibration and shock – is guaranteed.
When mounting as shown in examples 2 through 5, the position of the zero signal may be adjusted from the rear of the mounted encoder. When attaching the shaft preload coupling according to dimensioned drawing further down the page.
Mounting example including counter flange
Thrust disc DS 290
Possible pulse numbers GEL 293
The pulse numbers set in bold are standard pulse numbers.
Dimensioned drawing GEL 293 with counter connector GG106
Type code
Order details
Standard cable length: 1 metre. Please state in your order, if you wish other cable length. The counter connector GG 106 is included in the scope of supply, if the connector option is selected.
Order example For current outputs please state the nominal speed for Imax.
293 A V N 01000 L001; 3000 U min-1 = 20 mA
Lenord & Bauer: Rail Speed Sensors & Rotary Pulse Encoder
Other products relating to GEL 293 are: GEL 207, GEL 208, GEL 209, GEL 219, GEL 260, GEL 27xx
