Instruments For Testing Your Innovations
TS200 High-Curremp Amp Key Features
Output voltage range:
-
-
-
-
High output current:
3.5A RMS or 10A peak-
2.7A RMS or 7.6A peak-
1.4A RMS or 4.0A peak-
1MHz small signal bandwidth
Adjustable DC Offset
AC/DC Input couple
This App Note details how to maximize the TS200 output current. Maximizing output current is optional and it is intended for applications where the load impedance is too low.
Maximizing TS200 Amplifier Output Current
TS200 is a High-
Figure 1. Simplified diagram is showing how to amplify signal from a function generator to delivery high current to a heavy load without current maximization
Amplifier Current Optimization - Optional
The TS200 can drive heavy load and outputs high current for most application without any optimization as shown in Figure 1. In some applications such as driving magnetic coil or electrochemical reactor, where the highest possible current is desired, but don’t care about the voltage amplitude. The highest current is achieved when the TS200 is operating near its maximum voltage. If the load resistance or impedance is very mall, operating near the maximum voltage is not possible. In such case, a series resistor may be used (Figure 2).
Figure 2. A series resistor increases the TS200 operating voltage achieves the maximum possible current.
Selecting the Series Resistor
The series resistor will dissipate significant amount of heat. The amount of heat dissipated by the series resistor is given in the equation below.
P = (IRMS)2*R Warning: The series resistor may be hot!
where IRMS is the RMS (root-
The series resistor must be rated for that power dissipation. If high power resistor is not available, you can parallel several resistors to get the desired resistance and increase the total rated power dissipation. For example, you can use three 3-
Current Monitoring
As shown in Figure 3 (top), the series resistor can also be used for current monitoring. Place the resistor on the low-
I = V/R
where I is the load current, V is the voltage across the series resistor, and R is the series resistance.
If the load is ground referenced, load must be connected to the ground, swap the position of the series resistor as shown in Figure 7 (bottom). You still can measure the current, but needs two oscilloscope channels and configure them differentially (for example, channel 1 minus channel 2).
High Current Amplifier Application Examples
Relay
Solenoid
Magnetic coil
Helmholt coil
High-
Electrochemical reactor
Piezo element
Motor/actuator
Circuit characterization
Scientific and industrial testing
Automotive transient test
Laser Diode
Related App Notes
Table 1. Recommended peak voltage for maximum output current
For example, the TS200-
Figure 3. (Top) Low-
TS200 High-Current Amp Features
Figure 4 is the TS200 high current amplifier functional equivalent diagram. It features a selectable AC or DC coupled input. It also feature an adjustable DC offset voltage output which is useful if a fixed DC bias voltage is required. Two versions of the TS200 are available, the A-
Figure 4. TS200 high-current amplifier functional equivalent circuit.
(Optional)