Technical Guide to Precima Rectifiers for Brakes and Clutches
In industrial applications where motion control is critical, the interface between the power supply and the electromagnetic component is the rectifier. A wrong rectifier choice not only affects response time. It can shorten the life of the brake coil.
At EIDE, as specialists and distributors of Precima, we break down the technical capabilities of the most in-demand series for the Iberian market.
1. PMB Series: Bridge Rectifiers
Designed for full-wave conversion. Ideal when the DC output voltage must be approximately 90% of the AC input voltage.
- Input voltage (U_1): Up to 500 V AC.
- Output voltage (U_2): 0.9 x U_1 V DC.
- Rated current (I_N): Standard models up to 2.0 A DC (at 40°C).
- Protection: Integrated varistors on input and output to absorb voltage spikes and protect the silicon diodes.
- Application: Standard brake supply where a critical actuation speed is not required, but high current stability is.
2. PME Series: Half-Wave Rectifiers
An efficient solution for reducing consumption and heat dissipation. The output voltage is approximately 45% of the input.
- Input voltage (U_1): Wide range, up to 600 V AC.
- Output voltage (U_2): 0.45 x U_1 V DC.
- Load capacity: Built to withstand inrush current peaks.
- Mounting: Available for motor terminal box mounting or DIN rail mounting with adapter bases.
- Technical advantage: Lower brake coil heating in continuous duty.
3. PMG Series: Fast-Response Rectifiers (Push-Pull / Overexcitation)
The “gold standard” for applications with high switching frequency or critical safety requirements. These devices apply an overexcitation voltage (full-wave) for a short time (t_so) to overcome the inertia of the brake spring, then switch to a holding voltage (half-wave).
- Operation:
- Initial phase: U_2 = 0.9 x U_1 (fast opening).
- Holding phase: U_2 = 0.45 x U_1 (energy savings and lower thermal wear).
- Switching times: Brake release time reduced by up to 50% compared with conventional rectifiers.
- Thermal protection: Encapsulated electronics built to withstand vibration and harsh industrial environments (IP65 in specific versions).
| Parameter | PMB (Bridge) | PME (Half-Wave) | PMG (Fast) |
|---|---|---|---|
| U_2 / U_1 ratio | 0.9 | 0.45 | 0.9 / 0.45 (Overexcitation) |
| Max. AC voltage | 500V | 600V | 500V |
| Overvoltage protection | AC/DC Varistor | AC/DC Varistor | Integrated electronics |
| Operating temp. | -25°C a +85°C | -25°C a +85°C | -25°C a +75°C |
Customisation and Special Variations
As Precima partners, EIDE supplies versions that go beyond the standard catalogue:
- Rectifiers with integrated DC switch for ultra-fast disconnection on the DC side.
- Models with different cable lengths and specific terminals (faston, ferrules, or terminal blocks).
- Current variants: Units for high-current applications above the standard 2.0 A.
How to request the right rectifier
To guarantee compatibility, our technical team needs to know:
- Available mains voltage (VAC).
- Rated voltage of your brake/clutch coil (VDC).
- Coil current draw or power (W).
- Desired response time (standard or fast).
Optimise your braking system today with German engineering and local support.
📩 Request technical support or a quote: eide@eide.net
📞 Talk directly with product engineers: +34 93 714 65 11
