How to drive a nixie tube....



circuit 74141
SN74141
Integrated circuit SN74141 designed at Texas Instruments is most known. It is pin compatibel with predecesor 7441 from year 1976. The 7441 was produced by National Semiconductor.
Fairchild produced in year 1978 this same pin compatible circuit as "9315". Also in the Sowiets Union was produced this integrated circuit, fully compatible with 74141 It was labeled as "KM155ID1".

circuit HP1820-0092
HP 1820-0092
Hewlett Packard produced at end of 60-years an integrated circuit labeled 1820-0092. This circuit is not pin compatible with 7441 and/or 74141. Hewlett Packard uses this circuit in digital counters in that time usually with integrated circuits, counters labeled with code 1820-0093 or 1820-0119.

circuit N8T01B from Signetics
N8T01B
Integrated circuit N8T01B was produced by Signetics at end of 60-years last century. also this integrated circuit is not pin compatible with 7441 and/or 74141. The circuit N8T01B can be found in the digital nixie calculators from end of 60-years or maybe start of 70-years.

integrated circuit F9960 from Fairchild
9960
Integrated circuit 9960 was produced by Fairchild at end of 60-years last century. The circuit has RTL technology. The lowest power supply was +3.6 Volt and it could be controlled from TTL logic. It was used in test instruments and counters with nixie tubes.


The next circuit (Fig.1) shows a standard nixie tube driving (IN-12 made by Sowiets) by integrated circuit 74141. The integrated circuit 74141 receives data from asynchronous decade counter 7490.

nixie tube IN-12 with driver 74141

Fig. 1

The circuit in Fig. 1 has a disadvantage. In the event that circuit 74141 is without power and the Nixie tube is powered, the circuit 74141 will be destroyed. You need to project the power supply to avoid this situation.
If a Nixie tube driver is not available, it can be driven by transistors.

nixie tube IN-12 drived by transistors

Fig. 2

While circuit 74141 had only logic inputs A, B, C, D, the circuit of Fig. 2 still requires complementary inputs / A, / B, / C, / D. The connection in Figure 2 can be modified by generally using any circuit (decoder, memory, counter), which outputs one high state and nine low states. An example is a counter 4017 in the circuit of FIG. 3.

nixie tube IN-12 controlled by counter 4017 with transistors

Fig. 3

The values of resistances in the bases of transistors must be calculated according to the given situation (type of transistor, supply voltage, nixie type). The disadvantage of this connection is the need to use ten resistors for base control individual transistors. However, if we use a circuit (counter, decoder, memory) that will have an output only one Low state and nine High states, we can change the connection from Fig. 3 as shown in Fig. 4. The transistors are now driven into emitters and their bases are connected to a single common resistor. The condition is that only one transistor will be switched on at a time.

nixie tube IN-12 controled by decoder 7442 with transistors

Fig. 4

Circuit 4017 and essentially no other circuit of the 4000 or 4500 series can be used in the circuit of FIG. 4 because these circuits are unable to provide sufficient control current.