The MTT MS3786 Slim Plug-In Current Signal Conditioner (Isolator) takes a standard DC current or voltage signal and amplifies it into a much higher DC current output, up to several hundred milliamps, for driving loads that a conventional 4-20mA loop cannot supply on its own. This makes it a practical solution for powering high-current indicators, solenoids, or other actuators directly from a standard process signal without adding a separate power amplifier or relay stage.
An open-circuit detection circuit monitors the output and flags a fault through a photo MOS relay if the load is disconnected or the circuit opens, while a self-diagnosis function keeps watch on the supply voltage to catch power problems before they affect the output. Front-accessible trimmers allow zero and span to be adjusted on site, and an optional fast-response configuration is available for applications where the high-current output needs to track a changing input with minimal delay. Isolation between input, output, detection circuitry, and power keeps the amplified signal protected from noise and ground loops.
| Input Signal Types | DC current (100µA-100mA span) or DC voltage (200mV-20V span); input range -50 to 50mA or -10 to 10V |
| Input Resistance | 250Ω typical (current); 1MΩ min. (voltage) |
| Max Input | 40mA DC continuous (current); 30V DC continuous (voltage) |
| Output Range | -320 to 320mA DC; output span 20 to 640mA |
| Max Load Resistance | 50Ω at 200mA; 33Ω at 300mA; 31Ω at 320mA |
| Adjustment | ±5% of span, zero and span, via front trimmers |
| Isolation | Isolation between input, output, detection circuits, power, and ground; 100MΩ min. insulation resistance @500V DC; 500V AC dielectric strength for 1 minute |
| Open Circuit Detection | Photo MOS relay (35V/10mA max), activates if output voltage exceeds 11V |
| Power Supply | 24V DC ±10%; 6.5W max; 1.6A fuse standard |
| Accuracy | ±0.2% of span at 25°C±5°C; ±0.2% of span per 10°C temperature effect |
| Response Time | 160ms max (0-90%, step input); optional fast response mode (/K) 10ms max |
| Dimensions | W29 x H86 x D125mm |
| Weight | 120g (main unit) / 80g (socket) |
| Terminals | M3.5 screw terminals, 0.8-1.0 Nm torque |
| Mounting | Wall or DIN rail mount |
| Operating Conditions | -5 to 55°C, 5-90% RH non-condensing |
| Storage Temperature | -10 to 60°C |
| Additional Features | Self-diagnosis circuit monitors supply voltage drop |
Frequently Asked Questions
What is the MTT MS3786 used for?
It takes a standard DC current or voltage signal and amplifies it into a much higher DC current output, up to several hundred milliamps, for driving loads that a conventional 4-20mA loop cannot supply directly, such as high-current indicators, solenoids, or other actuators.
What output current range does it provide?
Up to ±320mA DC, with an output span of 20 to 640mA, configurable to match the load. Tell us the current your load needs and we can confirm the configuration.
What happens if the load is disconnected?
An open-circuit detection circuit monitors the output and flags a fault through a photo MOS relay if the load disconnects or the circuit opens, giving you a clear fault signal instead of a silent loss of output.
Is a fast-response version available?
Yes, an optional fast-response configuration is available for applications where the high-current output needs to track a changing input with minimal delay.
How do I know if the MS3786 is right for my application?
If you need to drive a high-current load, such as a solenoid or indicator, from a standard process signal without adding a separate power amplifier or relay stage, the MS3786 is built for that. Send us your load’s current requirement and your input signal type and we’ll confirm before you order.
Download MTT MS3786 Slim Plug-In Current Signal Conditioner (Isolator) information here
Datasheet: MTT_SpecSheet_MS3786_Rev110_E
