7228: Up to 60 Ap/160 Vp, DC to 1 MHz, Single-Phase

7228
Single-phase, 2U, industrial amplifier
- Up to 4X the long-term power of the 7224 at frequencies above 100 kHz
- Changes to protection, connection type and modes of operation are accomplished quickly by changing back-panel DIP switches or via remote contact closure
- Provides user-selectable current limit, DC Blocking and DC Servo for transformer-based loads
- Series or Parallel systems can be configured using back-panel DIP switches or remote contact closure. Ballast resistors are not required for connecting multiple amps in parallel
Key Performance Capabilities:
- Up to 1000 watts RMS power output
- Small signal response up to 1 MHz
- Up to 16A at 13.5 VDC
- Can be used to create series or parallel systems for up to 3 times the voltage or 4 times the current output
The 7228 is a 1-kVA, DC-enabled unit that provides advanced protection and exceptional versatility. It features a DC to 1 MHz bandwidth and improved performance at frequencies above 100 kHz. In continuous operation, a 7228 can provide up to four times the output power of the 7224 at frequencies above 100 kHz. If more current or power is needed, amplifiers can be combined in series or parallel and operate as a single system.
Back-panel switches allow the 7228 be configured by the user for high-voltage/low-current, medium voltage and current, or low-voltage/high-current applications. Residual noise, slew rate, and gain linearity have all been improved over the 7224 model. It can safely drive a wide range of resistive, inductive loads.
The 7228 is typically used to create waveforms as required by a variety of EMC standards for DC powered electronics like FMC 1278, DO-160, and MIL STD 461. It can also be used as a gradient amplifier for very small bore, high-gain MRI and NMR systems.
Output
AC Output
Note: Testing performed with fans set to Auto, 20°C ambient temperature, 1 kHz sinewave input signal into resistive loads as specified. Performance reported is typical into the specified load up to 20 kHz frequency levels. Performance may be affected when operating into highly reactive loads or above 20 kHz, reducing maximum voltage, current and power output. *Testing performed with Bi-level setting set to Manual, Low. **Continuous operation for 45 minutes..
High-voltage Mode
Ohms | PEAK OUTPUT |
RMS OUTPUT |
|||||||||
40mSec Pulse, 30% Duty Cycle |
5 Min, 100% Duty Cycle |
1 Hr, 100% Duty Cycle |
5 Min, 100% Duty Cycle |
1 Hr, 100% Duty Cycle |
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Volts | Amps | Volts | Amps | Volts | Amps | Volts | Amps | Volts | Amps | Watts | |
16 | 160 | 10 | 153 | 10 | 153 | 10 | 108 | 7 | 108 | 7 | 731 |
8 | 148 | 18 | 136 | 16 | 126 | 15.8 | 96 | 12 | 89 | 11.2 | 1000** |
4 | 120 | 29 | 90 | 22 | 63 | 15.7 | 64 | 16 | 45 | 11.2 | 500 |
2 | 92 | 45 | 47 | 23 | 47 | 23 | 33 | 16 | 33 | 16 | 550 |
Mid-level Mode
Ohms | PEAK OUTPUT |
RMS OUTPUT |
|||||||||
40mSec Pulse, 30% Duty Cycle |
5 Min, 100% Duty Cycle |
1 Hr, 100% Duty Cycle* |
5 Min, 100% Duty Cycle |
1 Hr, 100% Duty Cycle* |
|||||||
Volts | Amps | Volts | Amps | Volts | Amps | Volts | Amps | Volts | Amps | Watts | |
8 | 84.5 | 10.5 | 80 | 10 | 80 | 10 | 57 | 7 | 57 | 7 | 400 |
4 | 77 | 19 | 73 | 18 | 73 | 18 | 54 | 13 | 54 | 13 | 700 |
2 | 67 | 33 | 61 | 30 | 56 | 27 | 43 | 21 | 39 | 19 | 769 |
1 | 52 | 51 | 47 | 46 | 26 | 26 | 33 | 33 | 20 | 20 | 400 |
0.5 | 30 | 60 | 13 | 26 | 10 | 20 | 9.8 | 18 | 7.3 | 14 | 100 |
High-current Mode
Ohms | PEAK OUTPUT |
RMS OUTPUT |
|||||||||
40mSec Pulse, 30% Duty Cycle |
5 Min, 100% Duty Cycle |
1 Hr, 100% Duty Cycle* |
5 Min, 100% Duty Cycle |
1 Hr, 100% Duty Cycle* |
|||||||
Volts | Amps | Volts | Amps | Volts | Amps | Volts | Amps | Volts | Amps | Watts | |
2 | 33 | 16 | 33 | 16 | 33 | 16 | 24 | 12 | 24 | 12 | 273 |
1 | 29 | 28 | 28 | 28 | 28 | 28 | 20 | 19 | 20 | 19 | 388 |
0.75 | 26 | 34 | 26 | 34 | 26 | 34 | 18 | 24 | 18 | 24 | 452 |
0.5 | 22 | 43 | 22 | 43 | 22 | 43 | 16 | 31 | 16 | 31 | 488 |
0.25 | 14 | 53 | 11 | 45 | 11 | 45 | 8 | 32 | 8 | 32 | 256 |
DC Output
Note: Testing performed in high-current mode.
OUTPUT (Amperes) |
||
Volts DC | 5 Minutes, 100% Duty Cycle |
1 Hour, 100% Duty Cycle |
48.0 | 21 | 16 |
24.0 | 25 | 25 |
13.5 | 20 | 16 |
Performance
Frequency Data


Front & Back


DIP Switches
Settings, Configuration & Modes controlled by external DIP switches or remote contact closure
Sixteen back-panel DIP switches make it easy to configure the 7228 in the field.
- High-voltage, ±150 Vp; Mid-level, ±80 Vp; and High-current, ±40 Vp
- Stand-alone, Series, or Parallel connected
- DC blocked or enabled
- DC servo on or off
- Current limit on or off; level
- Input balanced or unbalanced
- Controlled voltage or controlled current
- Input ground lift
- Gain of 6:1 or 20:1

Specifications
Performance
Testing was done at 100 Hz. Continuous DC power levels are lower. See DC Specifications chart for test conditions.
7228 accuracy was measured when drivine into a 10-ohm load with between 0.1 VDC and 6 VDC or between 0.2 VAC and 5 VAC presented at its inputs.
Frequency Response,
DC - 1 MHz (1 watt): ±3 dB dB
Slew Rate: 100 V/µSec
Residual Noise,
10 Hz to 300 kHz: 900 µV (0.90 mV)
20 Hz to 20 kHz: 350 µV (0.35 mV)
Signal-to-Noise Ratio,
10 Hz - 30 kHz: –109.5 dB
10 Hz - 80 kHz: –106.3 dB
10 Hz - 500 kHz: –100.5 dB
Unit to Unit Phase Error: ±0.1 degrees at 60 Hz
THD (DC - 30 kHz): less than 0.1%
Output Offset,
With DC Servo Off: Less than ±5 mVDC
With DC Servo On: Less than ±400 µVDC
DC Drift: (after 20 minutes of operation),
With DC Servo Off: Less than ±1.5 mVDC
With DC Servo On: Less than ±200 µVDC
Output Impedance:
5.3 mOhm in Series with 0.95 µH
Phase Response (10 Hz - 10 kHz) :
0 to -5 degrees plus 750 nsec
propagation delay
Input Characteristics
Balanced with ground: Three terminal barrier block connector, 20k ohm
differential
Unbalanced: BNC connector, 10k ohm single ended.
Gain, Voltage Mode: 20 volts/volt; Current Mode: 5 amperes/volt
Gain Linearity (over input signal, from 0.2V to 5V), DC: 0.05%, AC: 0.15%
Max Input Voltage:
±10V, balanced or unbalanced
Status Display, Control, I/O
Front Panel LED Displays indicate: Ready, Standby, Fault, Over Temp, Over Voltage, Overload
Soft Touch Switches for: Run, Stop, Reset
Gain Control, when enabled: Voltage gain adjustable from 20 to 0
On/Off Breaker
Back Panel Power Connection: 25 Amp IEC (with retention latch)
Signal Output: Three-position terminal strip (OUTPUT/COM/CHASSIS GROUND)
Signal Input: User Selectable BNC or Barrier Strip, Balanced or Unbalanced
Communication Capabilities
Current Monitor: 5A/V ± 1%; 2.5A/V ± 1% (differential configuration)
Reporting: Run/Standby Status, System Fault, Over Temp, Over Voltage, Over Load, Temperature Monitor
Remote Control via Expansion Port: Blanking, Force to Standby, Reset after a Fault, DC Block, DC Servo, Control Mode, Bi-level Mode, Power Supply Rail Mode, Balanced/Unbalanced Input Signal, Series/Parallel Mode, Gain 20:1/6:1, Signal Ground, Current Limit
Protection
Over/Under Voltage:
± 10% from specified supply voltage amplifier is forced to Standby
Over Current:
Breaker protection on both main power and low voltage supplies
Over Temperature:
Separate Output transistor, heat sink, and transformer temperature monitoring and protection
Physical Characteristics
Chassis:
The Amplifier is designed for stand- alone or rack-mounted operation. The Chassis is black aluminum with a powder coat finish. The unit occupies two EIA 19-inch-wide units.
Weight: 41 lbs (18.6 kg), Shipping 51 lbs (23.2 kg)
AC Power: Single phase, 120 VAC, 60 Hz, 20 Amp service; (220-240 VAC, 50-60 Hz, 10 Amp service model available)
Operating Temperature:
10°C to 50°C (50°F to 122°F), maximum output Power de-rated above 30°C (86°F).
Humidity:
70% or less, non-condensing
Cooling:Variable-speed, thermostatically controlled cooling fans provide forced air cooling from front to back through removable filters.
Airflow:
180CFM
Dimensions: 19” x 22.75” x 3.5” (48.3 cm x 57.8 cm x 8.9 cm)
Downloads
7228 Datasheet
Complete technical specifications
7228-B Operator's Manual
For 7228 amplifiers built after 4/8/2018
7228-A Operator's Manual
For 7228 amplifiers built before 4/8/2018
Expansion Port Pinouts and Functions
For 7228 amplifiers
STEP file for Cabinets
For 7228 amplifiers
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