Question

When to use AC or DC on multimeter?

Answer 1

When you're using a multimeter, whether to measure AC (alternating current) or DC (direct current) depends on the type of electrical signal you're measuring. Here's a simple guide:

### 1. **Use DC (Direct Current) Setting When:**
   - **Measuring battery voltage**: Batteries (like AA, AAA, 9V, etc.) provide DC voltage, so you would use the DC setting to measure this.
   - **Measuring power supplies**: If you're testing a power supply that outputs DC (like in most electronics or circuits), use the DC setting.
   - **Testing circuits or devices powered by DC**: If your circuit is powered by a DC source (like most low-voltage circuits, electronic devices, or microcontrollers), set the multimeter to DC to check voltage or current.

### 2. **Use AC (Alternating Current) Setting When:**
   - **Measuring household voltage**: In most homes, the electricity supplied by your utility company is AC (like the 120V or 240V mains voltage in wall outlets), so you'd use AC mode to measure it.
   - **Measuring AC-powered devices**: For any appliances or devices that run on AC power, use the AC setting.
   - **Checking AC power sources**: If you're dealing with systems like transformers, generators, or AC circuits, set your multimeter to AC.

### Quick Tip:
- **DC** is constant and flows in one direction.
- **AC** constantly changes direction, and the voltage level alternates over time (like what you get from power outlets).

Just remember:
- For **steady voltage (like a battery)**, use DC.
- For **variable voltage (like from an outlet)**, use AC.

Let me know if you need help with anything specific on using your multimeter!