Relay Control Circuit Positive Feedback Timing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing relay control circuits fail to ensure reliable switching of relays within a specified time window, leading to undefined switching states and potential malfunctions in external systems due to insufficient switching duration and timing issues.
Innovation Solution
An electrical relay control circuit with a positive feedback mechanism and timers ensures the relay remains activated for the minimum switching duration by maintaining control through positive feedback when the first switching element is actuated within the time window, using a first transistor to interrupt power supply and a second transistor to extend activation beyond the initial time window if necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the relay is controlled by actuating the switching element within a time window, then the relay activation is limited to a specific time period, but the minimum switching duration may not be reached leading to unreliable switching
Solution Approach 1:
The circuit performs preliminary action by extending the relay activation beyond the time window expiration. When the switching element is actuated, the relay is activated not only during the remaining time window but also for an additional minimum switching duration, ensuring reliable switching regardless of when within the window the actuation occurs.
Solution Approach 2:
The circuit dynamically adjusts the total activation duration based on the actuation timing. By using the time window expiration signal and the switching element signal together to control the OR gate, the circuit automatically extends the activation period to ensure the relay remains activated for at least the minimum switching duration, adapting to different actuation moments within the window.
2Productivity
If the switching element is actuated shortly before the end of the time window, then the time window constraint is satisfied, but the relay may not complete switching leading to undefined states
Solution Approach 1:
The circuit prepares for potential incomplete switching by extending the activation period. The OR gate combines the time window expiration signal with the switching element signal, ensuring that even if actuation occurs just before window expiration, the relay remains activated long enough to complete the switching process reliably.
Solution Approach 2:
The circuit provides a cushioning extension period after the time window expires. This additional activation time acts as a buffer that ensures the relay has sufficient time to complete its mechanical switching process, preventing undefined states and contact bouncing that would occur with insufficient activation time.
3Reliability
If the relay switching duration is extended beyond the time window, then reliable switching is ensured, but the control precision within the time window is reduced
Solution Approach 1:
The circuit segments the control signals into distinct components: the time window definition signal and the switching element actuation signal. These segmented signals are processed separately and then combined through the OR gate, allowing precise time window control to define the activation opportunity while the extension mechanism ensures reliable switching completion without interfering with the original time window precision.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to an electrical relay control circuit (1) for controlling a relay (2) with a first switching element (3), wherein the relay control circuit (1) is configured to control the relay (2) by actuating the first switching element (3) within a time window, and the relay (2) has a minimum switching duration for a transition between two switching states, wherein the relay control circuit (1) comprises a feedback circuit (13) configured to maintain the control of the relay (2) for at least the minimum switching duration.