Schwarzbeck NFPA 9730 Power Amplifier DC - 250 kHz

The NFPA 9730 is a multi-purpose power amplifier and can be used within the frequency range from DC to 250 kHz. Typical applications are magnetic immunity testing according to automotive standards or MIL-461E or F.

Hazard warning:
The input signal must be switched off every time wires are being connected or disconnected.

Attention: Life-endangering high voltages occur at the terminals of the NFPA 9730 during operation. If used in an inappropriate way this could lead to a life-threatening situation for the user

Danger to life!

After turning the NFPA 9730 on a switching on delay circuit becomes active. It limits the startup current to 7A. After approx. 3 sec. the green „READY“ LED lights up and 1 more second later the signal input terminal (BNC jack) is activated. Now the amplifier is ready for operation.

After turning off the amplifier you have to wait 2 seconds before turning it on again.

The output voltage of the power amplifier NFPA 9730 is at the maximum when a level of approx. 2.5 Vrms is applied to the input and the LEVEL-knob is set to “10”. The „INPUT“ signal is limited to 5Vpeak internally.

In case of an overload „OVERLOAD” „I” (approx. at 30 Arms) the output will be disabled. A warning beep will indicate this overload. After the drawn current is reduced the output signal will be switched on again. “OVERLOAD” „U“ indicates a voltage limitation of the output signal. The use of an oscilloscope is recommended to monitor the output voltage.

The amplifier comes with a DC-coupled input and can be used as a DC-voltage source. The load impedance for frequencies lower than 15 Hz or for DC testing should be at least 1.0 Ω. Using the amplifier with loads of 0.5 Ω or 0.25 Ω is only allowed with reduced currents up to 13 ADC or 12 ADC respectively.

The amplifier is fused with a slow blow fuse, 10 A on the primary side and one fast acting fuse each, 25 A on “+Ub” and “-Ub ” on the secondary side.

The signal can be tapped from the red wing terminal. The blue wing terminal “COMMON” is connected to the housing electrically.

In case of overheating the input signal will be internally switched off and the red LED „OVERHEAT“ will indicate this case. Then you have to keep the amplifier running with fans on and input signal off for at least 10 minutes until the LED “OVERHEAT” turns off and the input signal is activated internally again.

Please note that the air intake for cooling purposes is located on the sides of the amplifier and the warm air is exhausted at the back. The amplifier must not be installed closer than 10 cm to a wall. It has to be installed in a way that the exhausted warm air cannot get into the housing again (thermal short). Pay attention to cooling especially when installing the amp into a 19” rack!

A 19’’-rack mount kit is available optionally.