Does Low Voltage Drive Affect The Performance of Micro Solenoid Valves?

Low voltage operation can significantly impact the performance of micro solenoid valves, affecting their functionality, reliability, and lifespan. Here’s a detailed analysis of key impacts and considerations:

1. Incomplete Actuation and Response Delay

A. Reduced Magnetic Force:

Low voltage air solenoid valve rely on electromagnetic coils to generate force for moving the plunger/armature. Voltage  directly affects coil current .  20% voltage drop reduces current by 20%, weakening magnetic force. This may cause incomplete opening/closing. The plunger fails to fully seat, leading to leakage.

B. Slower response time:

A 12V micro solenoid valve that opens in 10ms at rated voltage may take 15–20ms at 9V, impacting timing-critical applications.

C. Minimum Operating Voltage Threshold:

Below a certain voltage , the micro solenoid air valve may not actuate at all. For a 24V valve, this threshold might be ~19V; below this, the plunger may vibrate without moving, causing noise and overheating.

2. Increased Power Loss and Overheating

A. Inefficient Energy Conversion:

While low voltage reduces nominal current, incomplete actuation can lead to prolonged “in-between” states where the coil draws current without full mechanical output. For example, a 12V valve at 9V may draw 0.5A  due to stalled flux, increasing power dissipation  by ~56%.

B. Thermal Degradation:

Excessive heating damages insulation and weakens the magnetic core, reducing lifespan from 1 million cycles to 500,000 cycles or less.

3. Reliability and Leakage Risks

A. Sealing Failure:

Inadequate magnetic force may prevent the plunger from pressing tightly against the seat, causing internal leakage. In a fuel injection Mini 3 way solenoid valve 12v, this could lead to inconsistent flow rates .

B. External leakage: In medical devices, even trace leaks can compromise sterility or measurement accuracy.

C. Sticking or Jamming:

Low voltage may fail to overcome friction , causing the plunger to stick. For a 2 way mini solenoid valve 12v in a robotics gripper, this could lead to missed actuation or inconsistent grip force.

4.Impact on Duty Cycle and Longevity

A. Reduced Duty Cycle:

A micro solenoid valve rated for 100% duty cycle at nominal voltage may require intermittent use at low voltage to avoid overheating. For example, a 24V valve used at 20V in a continuous-flow system may fail after 500 hours vs. 1000 hours at rated voltage.

B. Mechanical Wear:

Inconsistent actuation increases wear on moving parts like O-rings and  springs. A valve designed for 100,000 cycles at 12V may only last 50,000 cycles at 9V due to repeated stress from incomplete strokes.

5. Mitigation Strategies

A. Voltage Regulation:

Use a voltage regulator  to maintain stable voltage

B. Select Wide-Voltage Valves:

Choose models with a broader voltage range (e.g., 9–36V for a 24V-rated valve) to accommodate fluctuations.

C. Optimize Circuit Design:

Add a transient voltage boost circuit for startup  to overcome initial resistance.

D. Load Matching:

Reduce mechanical load use a lower-pressure spring if operating at low voltage to minimize actuation force requirements.

C. Example Scenario

A 12V micro solenoid valve in a portable medical ventilator, powered by a 9V battery, may exhibit:

15% slower inhalation/exhalation timing

8% leakage in the closed state

Coil temperature rising to 75°C , risking premature failure during a 24-hour use cycle.

In summary, low voltage compromises micro solenoid valve performance via reduced actuation force, thermal stress, and reliability issues. Proper voltage management and component selection are essential to maintain functionality in low-voltage applications.