so, what about the circuit ? question : charge a 450V capacitor with a small battery such as a 1.5V or 9V ...to provide a voltage near 450V for the capacitor?...answer : Geiger counter tubes use in that vicinity of voltage and the following contains a simple power supply ! Probe Philips 18504 Tube with high voltage

LINK : https://electronics.stackexchange.com/questions/86617/charging-a-small-100uf-450v-capacitor-with-a-small-battery

https://www.ebay.com/…/Geiger-Counter-Probe-P…/162867268273…

Geiger Counter Probe Philips 18504 tube. Hayco | eBay

Used geiger counter probe. Has banana plugs for the connectors could be easily changed to whatever connector you need. Please look at Photos…

EBAY.COM