The TLN-864 Switching Comparator combines a comparator and an analogue switch. A typical comparator has two inputs (A & B) and produces an output that is high (H) if A > B, and low (L) if A < B. Rather than using fixed voltages for the H and L states, the TLN-864 allows the voltages to be manually set using two front panel pots. For example, H can be -1V and L can be +3V. In addition, two front panel jacks allow any external signal to be used for the H and L states. For example, H could be the SINE wave output from an oscillator and L could be the inverted output from a sample and hold module. Anything goes in, anything goes out. Reversing attenuators are used on the A, B, H, and L inputs so that all input signals can be scaled and inverted. When nothing is plugged into the A, B, H, and L inputs, the front panel pot is used to select a fixed voltage reference from -5V to +5V.
The switching portion of the comparator has two modes of operation. The first mode (HL:X) is a 2-to-1 switch in which the signals at A and B determine which of H and L appear at output X. In other words:
If ( A > B )
X = H
X = L
The Y output is not used in this mode.
The second mode (H:XY) is a 1-to-2 switch in which the signals at A and B determine whether H appears at the X or Y output. In other words:
If ( A > B )
X = H
Y = H
The L input is not used in this mode.
The panel controls are as follows:
- LEVEL A: reversing attenuator for A input (normalled to +5V reference).
- LEVEL B: reversing attenuator for B input (normalled to +5V reference).
- LEVEL H: reversing attenuator for H input (normalled to +5V reference).
- LEVEL L: reversing attenuator for L input (normalled to +5V reference).
- MODE: selects the switch mode, 2-to-1 or 1-to-2.
- LED: indicates if A is greater than B.
The TLN-864 makes a great companion to the TLN-865 Trigger Extractor & Window Comparator.
Note that the panel layout for this module (and the rest of my MUUB utility modules) uses the smaller type of knob found on Encore Electronic's UEG and Frequency Shifter. Most people will probably hate this, but I wanted to get the most functionality in the least amount of space while still maintaining some semblance to the MOTM standard. To this end, all of my MUUB utility modules use a new layout grid that allows up to 6 pots with 4 jacks, or 4 pots with 8 jacks, on a 1U wide module.
The TLN-864 Switching Comparator can be built using MUUB daughterboards.
Contact me if you wish to purchase PCBs.
Total current draw for TLN-864 is 30 mA @+15V and 25 mA @-15V.