Proteus reported an error during the 555 timer simulation: [SPICE] Too many iterations without convergent.
When the blogger was designing the course, he encountered a problem.
When using a 555 timer in proteus to build a 1Hz pulse generator, an error will be reported: [SPICE] Too many iterations without convergent. This is a headache, because there are no good replacement chips that can provide a pulse clock signal for the countdown circuit .
problem causes
Analyze specific issues. The error is reported because the proteus8.6 version has updated some content, so that the 555 timer that can be used normally in the previous version cannot be used in the version after 8.6.
Solution
1. Replacing the version
Replacing proteus with a version earlier than 8.6 can solve this problem. But as far as project stability is concerned, bloggers do not recommend this, and there is no way to ask the person who receives the project to change the version.
2. Replace the chip
The 555 timer has a "brother" version in proteus, that is NE555.
As shown in the picture:
choosing this chip can solve the above problems, but it will also report an error for the 74LS192 chip, so it must replace the 74LS192 in the countdown circuit with 74S168. See another blog for details : click here
3. Increase the resistance
This method is also the simplest method, that is to add an innocuous resistance at the output end of the 555 timer.
As shown in the picture:
After adding a small resistor, all the bugs disappeared.